This is a one-shot story, written by Leah "daughter of Alan" Moore and her husband John Reppion. The plot is relatively simple, but deals with the thematic content of new school Who very adroitly, much better than it's often handled on the telly, IMO. The people of the planet Grått repress their emotions, which the Doctor obviously thinks is a terrible thing because he's entirely lacking in self-awareness. On death, their final thoughts -- generally, the things they could never say in life -- are recorded by speaking portraits in the "Whispering Gallery" of the title (shades of the data ghosts thing in the Moffat Library story). The TARDIS lands in this gallery, and the Doctor is shocked to find the portrait of Grayla, a Gråttite who he briefly picked up between Runaway Bride and Smith and Jones and took away (at her request) because she didn't want to repress her emotions. He didn't ask her to become a full-time companion, because he was still being emo, apparently. The Doctor is shocked a) that she went back at all, b) that's she dead now and c) that her final thoughts are directed at him, so he goes off in search of answers, telling Martha to stay in the gallery because even the slightest bit of chirpiness would be too shocking for the Gråttites to cope with (whereas he, of course, can repress very well).
Stuck in the gallery, Martha starts listening to the portraits and realises that many of them are speaking to each other. She starts rearranging them on the walls so that they can hear their messages for each other, but nothing changes as a result. There is a nod to her unrequited love arc here, with her wondering why they never said anything, and IMO it's nicely handled.
The Doctor, meanwhile, finds Grayla's grave and the source of the problems: an "empathivore" that feeds off emotions. The Gråttites defeated it by all that repressing, but when Grayla came back, inspired by the Doctor's example to tell the others to start showing their emotions, it returned. The Doctor defeats it by overloading it with his Gallifrey emo, which sounds like it should be AWFUL but actually works really well, partly because of how well it's portrayed (the monster -- which is a big black smudge of a childhood fear sort of a thing -- getting bigger and bigger such that the speech balloon of him moping on is unreadable; I'll go on about the art a bit more in a minute) and partly because we're explicitly told that the Doctor's emo isn't anything particularly special -- if the Gråttites hadn't captured and sedated Grayla her joie de vivre would have done the same thing.
Anyway, as I say, the two major emotional notes of S3 -- the Doctor's emo and Martha's crush -- are there in the story in ways that resonate with it and are relevant, rather than shoehorned in as they sometimes are in the actual S3. There's also the "consequences of the Doctor's actions" thing that the telly repeatedly ducked out of (yes, I am still bitter that we never got the "btw, Doctor, this is your fault for deposing Harriet" scene), with the problems the inadvertent result of his encounter with Grayla in the first place. It's all very neatly done. I like it.
The art is by Ben Templesmith, who is apparently someone I should have heard of but in fact hadn't until now, essentially because I'm the sort of terrible philistine that doesn't read indie comics unless they're media tie-ins. His art is a little odd -- there are lots of appropriately washed out colours for the Gråttites but there are moments of deliberate smushing of the art with photos of the Doctor and Martha. It does work overall, but the occasional photo bits distracted me from the flow of the story.
But anyway, good stuff, yes. I hope the other five IDW one-shots are of a similar standard.