What the Pool Doesn't Tell — Marlene at the Shore

The afternoon light makes a runway of the wet rock. Marlene takes two neat steps along it before crouching beside a pool, where something soft and jelly-like is attached beneath a ledge.

It offers no good angle. She shifts instead.

A ripple passes over its pale body. Marlene keeps her fingers on the dry stone, well clear of the water. She cannot identify it, and a closer look is not a licence to poke.

She remembers reading about trabectedin: an anticancer drug first discovered in a sea squirt, one of the soft-bodied animals called tunicates. Developed into a medicine, it has been used for certain sarcomas and ovarian cancers. An extraordinary journey for a substance whose story began in an animal most beachgoers might overlook.

The detail that stayed with her was stranger still. The drug interacts with tumour-cell DNA, but researchers in Milan found another effect: it can kill tumour-associated macrophages, immune cells recruited into helping a cancer grow and spread. Not only an attack on the tumour, then, but on some of its help.

“Terrible choice of employer,” she murmurs.

The creature in the pool contracts slightly. Or the water bends the light. She waits, unable to settle which.

Nothing here tells her that this animal makes anything useful to medicine. It isn't a labelled sample, much less a cure waiting to be scooped up. Yet she wonders what substances it makes, what they do in its small patch of sea, and how much of that chemistry remains unknown.

Marlene rises carefully. For once, she has no tidy reveal to offer: a pool, an unidentified animal, a question still open. She leaves it attached to its rock.