Molecular structure tattoo across the foot

Ward nine has been quiet since midnight. Mrs Okafor's drip needs checking, and Harold in bay three wants to know whether the dawn is coming yet. You tell him it is, and you mean it kindly. Walking back, you count the building blocks on your fingers the way your grandmother counted beads: a cysteine, a tyrosine, then the bridge of sulphur that holds two halves of the chain together, a stitch that will not be undone unless someone asks it to be.

Back at the bench you check the seal, the batch number, the expiry. That stitch is the part that matters. Break it and the thing becomes a string of letters, a shopping list, nothing that can do the job it was made for. You think of the consultant who once said most of medicine is just keeping things in the right shape for long enough.

At six the handover comes. You sign the log, leave the vial in its cold tray and step out into a grey car park where the first bus is already lit like an aquarium. You realise you have been holding your breath, and you let it go. Behind you the fridge carries on humming its one note, keeping everything exactly where it was put.