After his film gig falls through, Joey is reduced to a job in a casino and is desperate to keep it from his friends. But when Monica decides to celebrate her one-year anniversary with Chandler in Las Vegas and Phoebe tags along, his lies are uncovered. The holiday gets off to a good start - until Chandler discovers Monica has been in contact with her old flame Richard and cannot let it go, ruining their anniversary. Meanwhile, Rachel and Ross travel to Vegas a few days after the others due to commitments in New York. Whilst travelling, they begin a "prank war" that gets out of control.