Chuck, Sarah and Casey discuss the mission at Castle, and Morgan catches Chuck before they head out. He gives him his sub-mission details: locations (he's chosen a balcony overlooking the garden and a couple other places, but tells him to watch Sarah, who will show him to the spot). Chuck says there won't be a sub-mission, but Morgan's not really hearing it.
French chateau. Chuck and Sarah look lovely arm in arm at the wine event. Chuck's focused on all the beauty and romance, but Sarah tells him to keep his eyes open for Pierre. She admits it's romantic, though, and kisses him. She slips away, so he calls Morgan and tells him he's right. Luckily, Morgan's loaded Chuck's pockets with the ring and mints. Casey yells at Chuck about how he needs to work, since the nanochip isn't going to find himself, but Morgan advises Chuck to let Casey manserve him. Chuck fakes British and tells Casey to go search underground like a good manservant. He loudly asks him to put his slippers out for tonight, and Casey has to pretend he's happy to do Chuck's bidding. Sarah returns, and gives Chuck another kiss. Then they pull out a little nanochip search machine that tells them there's no signal here. They walk around the chateau until they end up on the balcony Morgan showed Chuck. Sarah gasps at the beauty and Chuck realizes he's just been led to the place to do the sub-mission. He calls Morgan on his watch, which really never stops looking ridiculous, and tells him the sub-mission is a go. Chuck starts to approach Sarah with the ring, when Casey calls from his own watch downstairs and tells him he's got a signal, so good call sending him down there.
When Pierre and his gang enter the wine cellar, Casey tells Chuck he's down there and hides in a side room. The bad guys find the syringe gun (but the CIA didn't? How strange), and Pierre licks the end of it, realizing it's wine. He can even tell which kind it is; he's a super-wine-loving bad guy, of course! Casey calls up to tell Chuck and Sarah what bottle of wine the nanochip is in, and he says the signal's getting weaker, so the bottle's on the move. Chuck and Sarah head back to the party to find the wine bottle, as Pierre hears Casey and tells his men that no one gets out of here alive. Which is a perfect time for a commercial break.
When we're back, Chuck and Sarah head downstairs and quickly get a nanochip signal. Chuck thinks the bottle's outside, so Sarah tells him to get the wine; she'll get Casey. Morgan calls in to check on the sub-mission, but Chuck says he's sort of busy chasing a bottle of wine. Which he promptly loses outside, because there are so many bottles, which somehow weakens the signal (?). I don't know. Don't apply logic to it. He tells Morgan, who looks up the wine, an '86 Chateau Le Franc, which is a peppery pinot with a stable on the label and stork on the cork. Chuck continues to talk into his watch in full view of everyone at the event as he looks around frantically. He doesn't stick out at all at this mellow, classy gathering.