Bate --, accompanied by the mischievous music the show employs anytime someone's doing something crafty/silly/ill-advised/all of the above -- is putting the finishing touches on a forgery of Molesley signature, using the one on the card as a guide. Bates, your heart's in the right place, but you going to prison didn't work for you or me the first time, so be careful, okay?
As they dance, Jimmy James tells Anna he got tickets for him and Ivy to see Phyllis Dare, while nearby, some tough tries to cut in to dance with Rose, and even though she doesn't want to, he makes a thing of it and punches are soon thrown. Rose starts slapping at Sam's antagonist to the point where I really thought she was going to take one in her mannered kisser, but Sam calls for Jimmy James to get her out of there, and he and Anna quickly oblige just ahead of the cops coming to break things up. I'm guessing this isn't going to make Rose any less hot for Sam should she ever see him again, but what are the chances?
Molesley tentatively turns up to dinner below stairs, Thomas giving him a hilariously bored look before Bates tells him he was going through his desk that afternoon and came up with "that note" -- long story short, Bates is pretending that Molesley lent him some money when he first arrived at Downton and has written up a false note and forged Molesley's signature to it to support the lie. Obviously no one should buy this -- even leaving aside the fact that Molesley would surely recall lending Bates such an astronomical sum (it's thirty pounds), and that's granting that he would have been willing and able to do so -- the paper itself would show its age; remember about a decade has passed in the show's time since the first season. However, it's possible everyone is essentially clued in to this but that Molesley (never the sharpest knife in the drawer anyway) is willing not to look too closely at the situation given that it allows him to save face, which I suppose is fine. Lots of time spent on Molesley the past two episodes, though, no? I can't imagine much of the audience finds him particularly interesting, and I'd have no problem with the show keeping him strictly for comic relief (in limited doses, because his clumsy/clueless shtick gets old pretty fast). Anyway, there's a predictable fuss over it, but Bates hands over the money and gets out of there, whereupon Anna chases after him and he tells her he did it for her. She asks how he managed it, and he smiles that he keeps telling her: "Prison was an education." Yeah, but the boring kind.