It's Mother's Day again when Earl remembers that he has never given his mother a Mother's Day gift. Just as he and Randy are about to finish carrying out his long overdue gift, his mother decides her repayment should include Earl doing something for his father.

As things heat up between Randy and Donna, the gang discovers their growing relationship despite Donna's efforts to keep it a secret. But when Kitty insists that Eric and Donna are meant to be together, Donna questions whether dating Randy is the right move. Meanwhile, Fez tries to impress the ladies by creating a new persona at the salon and gets a little help from smooth '70s icon Isaac Hayes.

After their falling out, Ryan debates whether or not he should invite Marissa to his 18th birthday party, while Sandy urges Ryan to invite one of his relatives. After months of putting it off, Neil and Julie finally tell the truth to Summer and Marissa, respectively. Meanwhile, Ryan and Sadie's relationship, as well as Marissa and Volchok's, continue to progress.

A routine office day is changed when children come to Dunder Mifflin for "Take Your Daughter to Work Day." Michael is surprised when he strikes up a friendship with the five-year old daughter of his sworn enemy, Toby. Pam is desperate to befriend her colleagues' offspring, and a misunderstanding puts Ryan under Stanley's thumb.

A nervous but optimistic Grace decides it's finally time to tell Leo she is pregnant with his child, but when she finally works up enough courage to actually meet her ex-husband she receives some unexpected news Meanwhile, Will is settling in comfortably with James until he reveals a side of himself unknown to Will And as Jack attempts to document every moment of Grace's pregnancy for his talk show, Karen sulks alone, jealous over the good fortunes of her friends.

Sam is given an assignment at work to make a low-cost airline carrier, but he may not be able to deliver his proposal because of a tequila challenge he took part in the night before.

Armand Assante guest stars as a patient who makes Sam an offer she might not be able to refuse. Luka must calm Abby's baby-related fears after an incident at the hospital places everyone at risk. Kerry makes a difficult choice, and Neela joins a support group.

TONIGHT: Actor and star of Find Me Guilty, Vin Diesel!

TONIGHT: Stephen Colbert welcomes the author of A Guy's Guide to Being a Man's Man, Frank Vincent!

After two seasons of clashes of methods, Mickey and Danny finally put it all on the line. In a head-to-head competition, the two men are dropped naked in the middle of London and must use all of their skills as con men to make it through the day - whomever has acquired the highest monetary value of goods wins. The rub is that if Mickey loses, he declares that he'll hand over the role of leader to Danny. Are big changes a foot? Will Danny's moxie ultimately win him control of the crew?

Christian Slater, Johnny Vegas, Lauren Laverne and Rob Rouse join host Jimmy Carr and team captains Sean Lock and Dave Spikey.