Of course, in Fringe land it's not as easy as riding in a delorean to break the time-space continuum. Christopher Lloyd a washed-up musician who's now-dead son came 25 years into the future to see him. And he happens to be Walter's musical idol.
I, for one, would love to see Christopher LLoyd come back on the show often as Walter's best friend. They could have a bromance!
You can watch the entire episode on Hulu by clicking here.