- Josh Radnor (Ted Mosby)
- Neil Patrick Harris (Barney Stinson)
- Jason Segel (Marshall Eriksen)
- Alyson Hannigan (Lily Aldrin)
- Cobie Smulders (Robin Scherbatsky)
- Cristin Milioti (Tracy McConnell)
How I Met Your Mother — S4E24
Episode: The Leap
Air Date: 2009-05-18
Runtime: 23 min
Overview
Ted is trying to keep his architecture firm afloat by doing an all-nighter, but Marshall tries to lure him to the roof for a surprise 31st birthday party, on the fourth season finale.