What Lies in the Multiverse

• Chapter: 4
• Location: Casino
• Requirement: wait until Everett is done with his gambling game
• Story-related? No; if missed on your first playthrough, you can use chapter select

In last part of the chapter, you'll enter the Casino. As soon as you go inside, you'll find Everett sit at a gambling table. Talk to him and he'll ask you to wait a minute until he finishes what he's doing.

Simply don't proceed any further. Stay around him for one minute or so. He'll talk to you again saying he's ready and achievement will pop right away.