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...
I'm going to be infected! 
I-If that virus capsule bursts...
سـ-سوف أُصاب! إ-إذا انفجرت كبسولة
...الفيروس هذه
Ich werde infiziert. W-Wenn
die Kapsel mit dem Virus bricht …
¡Me va a infectar! Si estalla
una de las cápsulas con virus…
¡Me va a infectar! Si estalla
una de las cápsulas con virus…
Il va m’en mettre une…
Et si une capsule se brise…
Finirò infettato... Se una di quelle
capsule di virus si rompono...
Vou ser infectado!
Se uma das cápsulas de vírus estourarem...
Сейчас врежет! Тогда капсула
с вирусом разобьётся…