Reach into the cabinet under a kitchen sink with a pull-down faucet, and there is a hose disappearing up through the spout, with a plastic or metal weight clipped onto it partway down.

Somewhere on the water line under your kitchen sink, printed lengthwise along the tube in type about an eighth of an inch tall, is a line of text.

Fill a clear glass straight from the tap and hold it up to the light.

The vanity in the hall bathroom holds the usual inventory: a hair dryer with its cord wound around it, a basket of half-used bottles, a stack of towels somebody folded once, and a box nobody has opened since the move.

You reach down to unscrew the garden hose from the spigot, and instead of the hose letting go, the whole faucet turns with it.

Search for how long PEX plumbing lasts, and one claim turns up within a minute: that plastic supply pipe breaks down in chlorinated water, sometimes with several years attached, sometimes with a warning that a PEX repipe is already on a clock.

The handle is turned as far as it will go, and water is still finding a way out: a slow bead at the spout, or a damp patch seeping from underneath the handle itself.

Two houses stand on the same street, built the same year by the same builder, with the same rooms in the same order, the same bathroom at the same far corner of the plan.

You have already run the test without quite meaning to. Every other faucet in the house — the bathroom sink, the tub, the hose bib outside — delivers a normal stream.

A cartridge sits on a paper towel on the counter, pulled from a faucet that would not stop dripping.

Turn the handle and water shows up right away, tracking down the base of the spout or beading along a seam near the handle.