Inside the envelope is a single slip of paper with a hand-drawn white tulip .
At the end of Season 5, after time is reset to 2015 and the Observer invasion is prevented, Peter finds an envelope in his mail from Walter. Fringe - Season 5
Because Walter had to sacrifice himself by traveling to the future to reset the timeline, he is erased from 2015. The paper serves as a wordless goodbye, signaling to Peter that Walter succeeded and is at peace. 📼 Other Important "Papers" in Season 5 Inside the envelope is a single slip of