The person hiding in the mirror was Illuso from the Hitman Team. Fugo ends up being dragged into the mirror by Illuso's Stand, Mirrorman. Fugo then summons his own Stand, Purple Smoke. Despite Giorno wanting to find Fugo, Abbacchio decides to go look for the key, since that was their mission. However, once Abbacchio finds the key, he also gets dragged into the mirror world...
Whoops, so close. But you're a bit too late.
بئساً، كان ذلك وشيكاً. لكن تأخّرت قليلاً
Tja, knappe Sache.
Aber leider bist du zu spät dran.
Casi, pero demasiado tarde.
Casi, pero demasiado tarde.
Tu y étais presque, vraiment !
Ops, c'eri quasi. Ma ormai è troppo tardi.
Opa, por pouco!
Mas chegou tarde demais.