Pesto

Sammy Stevens, stuck in boring job, goes on bad dates

On one date he reminisces about his imaginary doppelganger named "Pesto"

Flashbacks to early puberty and teenage years showing Sammy's sad reality vs. his adventures as an idealized self ("Encendras") with Pesto in his imaginary alternate world (world 3)

Suddenly the "real" Pesto, Preston Chariot, arrives at Sammy's workplace

He half takes Sammy under his wing and half tortures him while speaking in weird riddles

Sammy has a simple ongoing flirtation with Braid, a woman he works with; she obviously hates him and seems awfully chummy with Pesto

Eventually he has to escape a bad situation with Pesto back to the non-imaginary parallel world Pesto comes from (world 2)

Pesto tries to sacrifice Sammy but gets taken prisoner; Sammy does not understand the convoluted laws of world 2 AT ALL

Sammy explores world 2 looking for answers but only finds more questions

Pesto sends an emissary - version 2 of Braid, whose name is Sympythy - to beg Sammy to save him 

They work together to try to corrupt the system; Symmy is much cooler than world 1 version and appreciates Sammy for who he is

World 3 Sammy ("Encendras") arrives to save the day

Saving the day consists of uncovering Pesto's unspeakable evils and ensuring he is never released

Sammy and Symmy get married (Encendras officiates) and split their time between worlds 1 and 2