REBORN! - Season 4 Episode 101 Night Attack
Overview: Tsuna and the others prepare for their attack the next day. They've been given Marmon covers on their rings which will hide them, dying will resistant clothing, and a communication system. Meanwhile the Millefiore digs their way underground and ends up at where the transmitter was. It turns out Hibari noticed the transmitter and carried it there to lure the Millefiore members away from the base.