Board Thread:Legitimate Canon Questions/@comment-26375697-20150514195741/@comment-4091815-20150515012248

Isaac Hayes was a singer-songwriter. I think you mean Isaac Lahey.

Isaac is last seen leaving the Argent apartment with Chris who is on his way out of town. It is assumed that Isaac left with him.

There is some external information that supports the assumption. Jeff Davis said in a couple of interviews that they were both heading to France and that Chris would return in Season 4 but Isaac would not.