Tom is furious after finding out that Lytell has taken his son Kyle into custody. Diana offers to help him in getting Kyle back. Meanwhile, Richard suspects that Collier is trying to take control of Lily's life, and as soon as Collier reveals his intentions, Richard and Lily leave Arcadia Estates. Danny snaps at Shawn when he finds out that he and Nikki have slept together. Tom and Diana finally find out what really happened to the 4400, which leaves a disturbing question: is this the end – or just the beginning?

Rachel and Ross' prank war starts getting out of control. Meanwhile, Chandler makes the bet of a lifetime to fix his relationship with Monica.

The battle with Ichigo and Amagai comes to a close. Amagai finds out the shocking truth of his father's death.

Mulder obtains what could be the original and uncut MJ documents containing information about the government's knowledge of extraterrestrial life, which could lead him closer to the truth than ever before. But Mulder's enemies make sure he learns that there's a heavy price to pay for his much sought after truth.

Monica's Porsche shows up again, and becomes a conflict when Rachel finds out she is the only one who hasn't driven it. Meanwhile, Chandler and Monica go off to Vegas to find Chandler's dad and invite him (or her) to the wedding. Back at home, Joey proves his masculinity to Phoebe, while Ross and Rachel hit the freeway in the "bad boy."