Sirius is working himself into a brooding paranoia. Grimmauld Place is an echo of Azkaban and there is no progress in the warfront to uplift his spirits. Remus is honestly thinking if he doesn't get a breath of fresh air soon, he might just lose his old friend to his own demons. A jaunt outside, a simple mission gone awry and a slice of adventure can do wonders it seems. -Ootp