Although Fringe‘s infamous “special” 19th episode won’t air until April 20, Fox is already teasing what looks like a real mind-bender!

This episode is called ‘Letters of Transit,’ and Lost‘s Henry Ian Cusick guest stars. Looks like the Observers are involved, and John Noble teases to TV Line that he’s playing two new versions of Walter in this episode!

Bring on #April20thIsTheNineteenth!