Keith thinks he's about to get rickrolled. Keith is mistaken. When he opens the email, all it says is Saw this and thought of you, happy birthday buddy, followed by a link to a video hosted on a Google drive. Keith gives it a long look, weighing suspicion against curiosity, the fact that he knows the sender of the email against the fact that he knows the sender, and then shrugs suspicion aside. He's probably about to get rickrolled, but whatever. He clicks the link. It's not a rickroll.