How I Met Your Mother season 9, episode 20, “Daisy,” airs tonight at 8 p.m. ET on CBS. We’ll see the repercussions of the bombshell dropped on viewers at the end of last week: Robin’s mother arriving at the Inn.

We were not expecting it anymore than Robin was – and while Barney may appear calm and collected, according to the promo below, he is a little nervous to meet his soon-to-be mother-in-law. But, is her return simply a red herring for the more important aspect of the episode?

The official synopsis for ‘Daisy’:

Marshall enlists Ted and Barney to help him figure out where Lily went when she left in the middle of their fight, on the final season of How I Met Your Mother, Monday, March 10 (8:00-8:30 PM, ET/PT) on CBS.

Chris Elliot returns as Lily’s dad, and Kyle MacLachlan returns as the Captain. If you put two and two together, you realize that he somehow played a big part in the fight Marshall and Lily had once he arrived at the Inn earlier that weekend – or, for viewers, back in January in the episode “Unpause.”

Check out a sneak peek of the episode:

Here are official stills from ‘Daisy’:

Guess we know why Marshall is eyeing those swords! But, given How I Met Your Mother‘s perchance for having outlandish conclusions to these kinds of events, we wouldn’t be surprised if Marshall ends up with a shaved head, a la his own wedding.

We do want to know why and how the Captain (real name: George Van Smoot) factored into Lily’s acceptance of staying in the States and not jetting off to Rome to curate art for him. Perhaps he persuaded her to stay with Marshall to strengthen their marriage? As we know, Ted did have a hand in George Van Smoot’s own divorce to Emma Swan Zoey Pierson in season 6.

How to watch ‘HIMYM’ season 9 online

CBS does offer a free, legal replay of How I Met Your Mother episodes on their website to watch online the morning after an episode airs. Their video player can get a little spotty, but it’s hard to beat that low, low cost of free. iTunes also offers How I Met Your Mother episodes for purchase, and a season pass option as well.