Reverse, Opposite
Your scooter takes you to the barracks, drops you off, and then goes in reverse all the way back home in the opposite direction.
Imagine riding your scooter to the barracks. It literally drops you on the ground when you get there, and then drives in reverse back the opposite way you came.
ぎゃく
さか
None
Your scooter going in reverse and leaving you here is opposite of what you want. You want to ride it back home when you're done, so you stuff the wheels with Gak (ぎゃく). If you don’t know what Gak is, check out this Gak commercial.
You Gak up the wheels so when the scooter tries to switch to reverse it gets stuck. Success! But now it can't go forward either. Darn you Gak, you tricked me again.