season 1, episode 1.

Blue lightning struck around the courtyard as a portal appeared from the sky.

Luther: "everyone stay back!"

Allison and Diego: "What the hell-"

Then... Five appeared from the portal before it dissapeared as he collapsed onto the stone ground.

The family got close with confused looks as they looked down.

Klaus: "uhm.. do my eyes deceive me or is that little number Five?"