The One?

Rachel Bilson has landed a pivotal role in How I Met Your Mother’s 100th episode airing in January.

Show exec producer Craig Thomas has teased that the milestone episode would feature “some serious mother action,” adding that, “It’ll be the closest [we’ve] ever come to [discovering who the mother is].”

So now the question is: Is Bilson it, or is she another fake-out like Sarah Chalke and Jamie-Lynn Sigler?

Photo: Yahoo! TV.