Evan is teaching robotics at Mosman High on Thursday afternoon, so Declan has the choice of going home (with no-one home for an hour or so) or catching the bus to Mosman and joining them. Unfortunately last week, Declan forgot, and went home, promptly setting off the burglar alarm.
After his first attempt to turn it off failed, he rang Evan in hysterics, leading to much panic at both ends of the call, as Evan tried and failed to figure out why Declan was yelling, "help, help! with sirens in the background". Fortunately they eventually figured it out together, but not before Evan acquired several new grey hairs.
The positive to come out of the experience is that Declan has realised he's actually fine at home on his own, and will do that on Thursdays from now on.