The Office of Terror

You walk out of the office after a hard day of work. As you head towards your car, a thought goes into your head.
You say to yourself "Oh man, I forgot my work folder." You turn back around and start to head towards the building as you receive a text. Your friend texted you about the dinner party at his house. If you go back into the building and retrieve your folder, you'll be late to the party. What should you do?