The Mi'ihen Highroad Mystery is an optional sidequest in Final Fantasy X-2 and takes place during Chapter Four. Rin asks Yuna, Rikku and Paine to help him investigate two separate incidents that occurred during the game on the Mi'ihen Highroad; a hover crashing on the Oldroad and the sentry machina going haywire.
Participating in this sidequest is necessary for the player to earn an Episode Complete for the Mi'ihen Highroad.\
During the Eternal Calm, the inhabitants of Spira slowly began to accept machina. On the Mi'ihen Highroad, Rin installed several sentry machina to guard the highroad and protect travelers from fiends. In addition, hovers replaced chocobos as a more convenient means of travel. The presence of machina and hovers meant that chocobos are all but gone on the Highroad.
However during the events of Final Fantasy X-2 two separate incidents occurred. After the mission "Cuckoo for Chocobos" in Chapter Two, a hover, traveling from the Travel Agency to the North End, mysteriously falls off the Newroad and crashes in the ravine below. This incident closes the Northern section of the Mi'ihen Highroad for the remainder of the chapter.
In Chapter Three another incident occurred. The sentry machina on the Highroad malfunctioned and began to attack travelers instead of protecting them, prompting the Gullwings to battle and destroy the machina while the Al Bhed dismantled them. Following this incident, Rin launches an investigation into the hover crash and the machina malfunction.
During Chapter Three, Shinra installs a CommSphere outside the Travel Agency. In Chapter Four, when the Gullwings connect to the CommSphere, Rin asks the party to help him in his investigation by connecting to the CommSpheres he has placed around the Highroad and alert him if they find or see anything suspicious.
The results of Rin's investigation are revealed when the player visits the Mi'ihen Highroad in Chapter Five.
Five suspects can be blamed for causing the incidents on the Mi'ihen Highroad: The Chocobo Eater, Rikku, Calli, Prophet and Rin himself. Blaming the Chocobo Eater, Rikku or Calli will award the player Episode Complete for the area and allows them to ride chocobos on the Highroad; pinning the blame on Rikku will also award the player the Ragnarok accessory, which reduces the MP Cost of all abilities to zero. If Prophet or Rin is blamed, or if no suspect is blamed, the player receives an Episode Concluded for the area, and chocobos cannot be ridden on the Highroad, although pinning Rin the blame does reward the Gippal Sphere.
In Chapter Four, Rin asks the Gullwings for their help in his investigation on the Mi'ihen Mystery, but only if the player started the "Machina Mayhem" mission in Chapter 3, which allowed Shinra to install a CommSphere outside the Mi'ihen Travel Agency.
To allow the Gullwings to help him in his investigation, Rin installs six more CommSpheres covering the Mi'ihen Highroad. Rin asks Yuna, Rikku and Paine to connect to each CommSphere, and to call him if they see anything suspicious.
The CommSpheres are numbered one through eight and can scan the following areas:
- Outside the front of the Travel Agency.
- Behind the Travel Agency, where the sphere monitor controlling the sentry machina is located.
- The ruins at the South End of the highroad.
- The Newroad
- The Oldroad, where the hover crashed.
- The Oldroad, dead end
- The cliff between the Newroad and Oldroad (if the player returns to Mi'ihen Highroad - Newroad in Chapter Three after "Machina Mayhem", Shinra places the CommSphere here).
- The North End
Whenever the player sees anything suspicious, they should call Rin, and he will appear immediately in frame to investigate, This will add some blame to one of the suspects. When enough evidence points to a suspect, a jingle will be heard in the background, indicating the next stage of the investigation has begun. After the third stage ends, Rin's investigation is complete.
The following tables indicate what events the player should look out for. Note that depending on the player's actions during the game, some scenes will not play. For example, if the player picks up Calli after the events of Chapter Two, she will not appear in any vent.
|7||Rin talking to an Al Bhed woman (Rin doesn't know a CommSphere has been installed here).||Rin|
|2||The Chocobo Eater approaches the sphere monitor.||Chocobo Eater|
|8||The Chocobo Eater listens to Prophet.||Chocobo Eater|
|3||A Machina appears.||Rikku|
|5||A chocobo feather falls to the ground.||Calli|
|8||Prophet's Assistant talking to one of the Al Bhed.||Prophet|
|4||Prophet and his assistant talking.||Prophet|
|4||Skid marks leading to the ravine below.||All|
|1||Chocobo Eater chases after a bird.||Chocobo Eater|
|4||Chocobo Eater chases after a hover.||Chocobo Eater|
|1||Calli appears to the left of the Travel Agency.||Calli|
|2||Prophet's assistant examines the sphere monitor.||Prophet (call Rin)|
Calli (Don't call Rin)
|2||If Rin was not called when Prophet's assistant examined the sphere monitor, Prophet's assistant leaves, then Calli approaches the sphere monitor.||Calli|
|2||If Rin was called when Prophet's assistant examined the sphere monitor, an Al Bhed examines the sphere monitor (Do not call Rin and wait for at least 15 seconds after this event before connecting elsewhere).||Prophet|
|3||An Al Bhed runs toward Prophet.||Prophet|
|5||Three Machina runs to the hover and drags out the driver.||All|
|6||Prophet talking to two people.||Prophet|
|1||Rin talking to the hover driver.||All except Rin|
|2||Somebody hammering the roof of the Travel Agency.||Rikku|
|3||Somebody standing near the ruin.||Calli|
|4||Calli running off.||Calli|
|8||Prophet and his assistant talking.||Prophet|
|5||Large dent in the crashed hover.||Chocobo Eater, Rin|
|5||After a while, CommSphere suddenly breaks.||Rin|
|4||Rin doing something in the ravine (call Rin after Yuna wonders what he is doing).||Rin|
- "This fiend is truly an impressive creature. It has managed to thoroughly disrupt our daily affairs, even if it was just pure luck. Fiend or not, I admire it greatly for its tenacious pursuit of its goals."
- —Rin, after concluding the Chocobo Eater is responsible
The Chocobo Eater is arguably the easiest suspect to blame for the two incidents, as it requires a minimal amount of work on the player's part prior to the investigation in Chapter Four; to make the Chocobo Eater a potential suspect, one must start the "Machina Mayhem" mission in Chapter Three, which will allow Shinra to place the CommSphere in front of the Travel Agency.
As there are no more chocobos on the Mi'ihen Highroad, the Chocobo Eater was on the brink of starvation. It correctly surmised that machina are to blame for this, and if it destroys the machina, Rin would have no choice but to bring chocobos back to the highroad.
The Chocobo Eater first attacks a hover on the Newroad, knocking it down into the ravine below. Then, once it discovers the control panel behind the Travel Agency, the Chocobo Eater sabotages it to cause all the sentry machina to go haywire.
Rin is impressed with the Chocobo Eater's tenacity, and grants its wish to bring chocobos back to the Highroad. However the Al Bhed hauls the Chocobo Eater away, most likely to be killed.
- —Rikku, upon learning she was responsible
In order for Rikku to become a potential suspect, the player must complete the mission "Cuckoo for Chocobos" in Chapter Two. During that mission, the Gullwings must capture the chocobo at the South End of the Mi'ihen Highroad. During this, Rikku will drop down from the large ruin and land heavily on one of the sentry machina. As the machina were being synchronized, this would later cause the machina to malfunction. Capturing the chocobo before reaching the South End will prevent this event from taking place, meaning Rikku cannot be held responsible.
In the same mission, if the player reaches the Chocobo Eater before the allotted time is up, Rikku will be seen running across the bridge on the Newroad after the battle. A hover moving in the opposite direction tries to avoid Rikku, but ends falling and crashing into the ravine below.
The player can place Rikku into blame further during the Chapter 3 mission "Machina Mayhem". If the player jumps down the cliffside from the Newroad to battle the rogue machina, Rikku will leave her footprints behind, which will later be matched with the footprint imprinted on the machina's head back at the ruins. Jumping up from the Oldroad to battle the machina will not leave footprints behind.
After Rin's conclusion that Rikku's was responsible for both incidents, Rin decided that Rikku's punishment was to pick up litter on the Highroad. Rin later purchases chocobos for travelers to ride on. The chocobos then leave a trail of feathers behind, much to Rikku's exasperation.
- "Yes, I'm the one who did it. I thought if machina were gone, chocobos might return to the Highroad."
In order for Calli to become a suspect, the player must complete the "Cuckoos for Chocobos" mission in Chapter Two, but must fail to reach the Chocobo Eater within the allotted time. This would mean that Calli will not get a chocobo. Also the player must not allow Calli to board the Celsius after the mission, otherwise she cannot be responsible for the incidents.
Due to the failure of her not getting a chocobo, she pushes a hover into the ravine and then causes the machina to malfunction, in the hope of getting her wish to ride on chocobos on the Highroad again.
After hearing her confession, Rin punishes Calli by making her work at his Travel Agency. Some of her work involves looking after the chocobos that Rin has purchased, leading Paine to question whether or not this is a punishment.
- "That's right! Like, it was me! And I would've gotten away with it too, if it hadn't been for you meddling kids!"
Prophet is often found talking to passers-by promoting the use of chocobos instead of hovers. Pinning the blame on Prophet is easier by talking to him on every chapter. Also, taking the hover from the North End to the Travel Agency will show a cutscene where another hover going the other way will fall down the ravine trying to take evasive action, which adds to Prophet's guilt. Prophet's guilt will increase even more if the player initiates the mission "Machina Mayhem" from the North End, as the player will see Prophet running in the direction of Mushroom Rock Road.
In an attempt to get chocobos back to the highroad, Prophet pushes a hover into the ravine, then tricks the machina operator in telling him how the machina works, allowing him to sabotage them.
Rin punishes Prophet by forcing him publicize the use of hovers and machina, making him an Ex-Prophet. While pinning Prophet the blame results in a humorous cutscene, the player will only receive Episode Concluded and misses the chance to ride on chocobos.
- "I firmly believe that machina are an indispensable part of Spira's development. Even if there is another incident, I intend to conceal the evidence."
Pinning the blame on Rin is arguably the hardest of all suspects, as the player is required to undergo a lot of work with no margin for error. There are five tasks that the player must do before Rin's investigation, and missing one will mean Rin cannot be held responsible:
- In Chapter One, the player must visit the Mi'ihen Highroad - Central Area. In one of the inlets to the right of the highroad, there is an Al Bhed experimenting on some of the sentry machina, attempting to synchronize them. The player must talk to this Al Bhed.
- In Chapter Two, after the "Cuckoos for Chocobos" mission, the player must visit the Travel Agency. Rin will be seen leaving the Travel Agency as the party enters.
- In Chapter Three, during the mission "Machina Mayhem", the player must destroy more machina than the Al Bhed.
- Once the "Machina Mayhem" mission is complete and the prize for completing the mission is given out, the player must wait until they see Rin walking into frame before confirming.
- After the "Machina Mayhem" mission, the player must walk on the Newroad and talk to Shinra, who will tell the party that he has dropped a CommSphere down the cliffside.
During Rin's Investigation, the player must allocate blame against the Chocobo Eater in Stages One and Two, but they must ensure that they catch Rin on CommSphere No.7 in Stage One.
In Stage Three, Rin must not be called whenever the player connects to CommSphere No.1, or the Chocobo Eater will be punished. Instead the player should connect to CommSphere No.5 and call Rin, who will notice the dent in the hover. Next the player should connect to CommSphere No.1, then immediately reconnect to CommSphere No.5 and wait. After a while, the CommSphere will break suddenly. One should then connect to CommSphere No.4 where Yuna will spot the culprit Rin in the ravine. Once Yuna questions what Rin is doing, the player should call Rin, who will run up to the CommSphere to apologize, stating that he has business to attend to.
Finally the player should connect to CommSphere No.7 and wait for about ten seconds before calling Rin, even though no event has happened. The player should then connect to CommSphere No.1, the immediately reconnect to CommSphere No.7, wait for around 10 seconds and call Rin again. The player should repeat this cycle several times until it comes to a point where Rin will no longer answer Yuna's call. Once this happens, the player should disconnect from the CommSpheres immediately.
In Chapter Five it is revealed that Rin is to blame for the incidents. While attempting to synchronize the machina, one rogue machina went haywire and attacked the hover, knocking it into the ravine. As the machina were synchronized, all sentry machina became rogue and started to attack travelers. Rin, knowing his guilt, dismantled as many machina as possible while the Gullwings were destroying them and attempted to slip away from the scene without anyone seeing him.
Rin then enlisted the Gullwings for help in his investigation, knowing that they were amateurs and hoping that they will mess up the case. He tried to conceal evidence from the hover by breaking CommSphere No. 5, hoping he won't be caught, but was instead seen when the Gullwings connected to another CommSphere. The Gullwings then kept calling Rin, even though they didn't have any leads, but as Rin did not object to any of the interruptions, Yuna deduced that Rin was not intending to solve the case after all.
Rin argued that machina would soon be a integral part of Spira, and that he intends to cover up any more incidents involving machina. He gives Yuna the Gippal Sphere before leaving.