The Bokuto Station is called on to help with a multiple car crash in one of the tunnels.  Natsumi and Miyuki are asked for specifically to help and they find Toukairin there.  After apparently getting everyone out, one woman tells them that her son is still in there.  Natsumi and Toukairin head back in among the gasoline fumes to find him.  After it is all over, Natsumi hears from Toukairin that he is being reassigned and that he'll be leaving.