I have one Heart left, who is tagging it as we speak (or when I'm done throwing CR at Theo). Alasdair James Malcolm DeWitt here is a Deckbaby Heart, raised in the Castle by his parents, Catherine (A Ten and Director of Communications for the Hearts) and Dougal (An Eight and an inventor whose suffering from senility these days, and as such tends to make things explode accidentally). He's got three younger sisters, all younger and ranked higher than him.

He's also the secret author of a highly popular murder mystery series published by a major New York house, that is loosely based on Deck dramas. He keeps it a secret because he has some idea that being a genre writer is worth less than being a literary one.

Aaaanyway, I imagine he and Theo know each other? If Theo does any medical education/first aid classes at the school, they might have worked together in some capacity.

The only other two who are likely to know him are Jordan and Zoe; Zoe and Theo threaded once already, and seem to be friendly, and Jordan would have been a Ten with him. Given how standoffish he can be and how a lot of Hearts have treated him over the years, though, I imagine Jordan was probably polite but possibly pretty distant, especially after he and Hadyn got Laureline banished.