When Marshall gives Lucas the weird hug thing he gave him the first time his head is on Lucas' shoulder. The second time at the end of the episode Marshall's head is on Lucas' Stomach (Contributor: karategrl)
Corrine: (To Lucas) So you thought it would be fun to suck me into your tesseract?
Lucas: (To Professor Z) If there's a problem to do with hyper-dimensional math, Corrine's the one to call.
The Janitor is aware of the existence of the tesseract device, as he seems to know everything that has occurred connected with Blake Holsey and Pearadyne.
He sends the tesseract device, securely contained within a strange morphing box, to an unknown destination using one of his light slips at the end of the Tesseract episode, he also acknowledges Lucas Randall has seen and knows the function of the tesseract device.
a clip appears from Wormhole in this episode
Janitor's Secret Message: "Jealousy leads to disarray. The same mistake will not be made twice. He who was lost returns."
If you look carefully at Professor Z's laptop, you can see that he uses Microsoft Windows XP.