Looks like Desmond decided to take Donovan's advice; he's examining a display case full of rings in a second-hand shop (albeit a really nice one). An older woman, played by Fionnula Flanagan, if that means anything to you (it didn't to me, but apparently she's been all over television ["And movies, one of which was...are you ready?...The Others! Ooooooo! Okay, I'll stop now." -- Joe R]) approaches and guesses that he's never done this before: "I can always tell the first-timers." She asks what Desmond's price range is, and he sheepishly says he's "not a man of means." She graciously cuts him off as he starts to stammer out something about how he hopes to be rich one day or whatever, and says she has just the thing for him. She leads him over to another display case, where she takes out a simple yet quite beautiful diamond on a gold band. "This won't blind any queens, to be sure, but it still has the sparkle of life," she says, and Desmond takes it. He smiles, admiring it, and says he'll take it, which really comes as something of a surprise to Fionnula, and Desmond has to repeat himself: "It's perfect. I'll take it." But Fionnula snaps that he won't. Her friendly demeanour rapidly fading, she orders him to give the ring back. Desmond's right confused now, but Fionnula's explanation really doesn't help him: "This is wrong. You don't buy the ring. You have second thoughts; you walk right out that door. So, come on, let's have it." Desmond has no idea what she's on about, and says so, so she says again: "You don't buy the ring, Desmond." The fact that she knows his name only freaks him out more, but it turns out Fionnula knows a whole lot more than that: "I know your name as well as I know that you that don't ask Penny to marry you. In fact, you break her heart. Well, breaking her heart, of course, is what drives you in a few short years from now to enter that sailing race, to prove her father wrong, which brings you to the island where you spend the next three years of your life entering numbers into the computer until you are forced to turn that failsafe key." Desmond stares at her, but that's what he gets for not making sure to enter a second-hand shop that doesn't have spoilers. "And if you don't do those things, Desmond David Hume, every single one of us is dead," spits Fionnula, who holds her hand out again: "Now give me that sodding ring!"
We're back from commercial, and Desmond hasn't given back the ring. His open mouth is probably gathering a lot of flies, though. An annoyed Fionnula withdraws her hand. "Oh, you're going to be difficult about this, I can see." Desmond asks who she is. Instead of answering, Fionnula says, "Do you like chestnuts?" and walks away, leaving a befuddled Desmond in her wake.