At the end of a corridor on the second floor of Tel Aviv’s Sourasky Medical Center, there is a small room filled with six huge stainless-steel tanks. When a gloved hand lifts one of the lids, liquid nitrogen condenses, swirls and billows over the tank’s frost-encrusted rim, as if it were a magic cauldron.

“At any given second, we know that the temperature is right. It’s backed up, and monitored all the time,” the laboratory director, Dr Shimi Barda, tells me. “You can’t put a price on what we have here.”

What they have is the largest sperm bank in Israel. More than 53,000 sperm samples are stored here, in numbered vials or thin plastic straws, frozen at -196C. As well as samples from donors and IVF patients, there is sperm from men with cancer, frozen before their chemotherapy, and from trans people, before gender reassignment. Some of the samples even contain the possibility of life after death: sperm taken from the bodies of dead Israeli soldiers in the hours after they have been killed. In the nine and a half months following the Hamas attack on October 7 2023, sperm was successfully taken from the bodies of 160 soldiers and 15 civilians, according to data from the Israeli Ministry of Health.