It's the second week of November when the boiler at number 12 makes a sound Tom Morgan later describes as "a kettle being strangled" — and stops. No heating, no hot water, and Ellie has swimming trials on Thursday.

The engineer arrives next morning, spends twenty minutes with a torch and a frown, and delivers the verdict. The heat exchanger is failing. On a twelve-year-old boiler he can attempt a repair for about £600 — no promises how long it holds — or they replace the thing properly: £2,300 fitted.

Here's the Morgans' financial position, which Sarah could recite in her sleep because she does the budget planner every month: £900 in the emergency fund (they've been rebuilding it since the car's clutch went in March). A credit card with a £3,000 limit at 24.9% APR, currently clear. And Sarah's brother Dev, who mentioned at Sunday lunch — before the boiler knew it was dying — that he's "always happy to help out" since his bonus landed.

It's 4°C outside. The kids are wearing coats indoors and finding it hilarious. Tom and Sarah are at the kitchen table with a calculator and mugs of tea going cold slightly faster than usual.