Greg Kinnear guest stars as Dr. Hobart, eminent paleontologist, Nobel Prize winner, and former boyfriend of Ross' current amour, Charlie (Aisha Tyler). Anxious to get a prestigious grant from Hobart, Ross (David Schwimmer) is willing to many any sacrifice -- but he may draw the line when it comes to giving up Charlie. Elsewhere, Chandler (Matthew Perry) unsuccessfully tries to cover up the fact that he's sneak-previewed Joey's (Matt LeBlanc) audition tape, and Rachel (Jennifer Aniston) and Monica (Courteney Cox) get into a tussle over a painting that neither one wants -- or do they? ~ Rovi