 What transpired after this is a matter of debate.The earliest, and therefore probably most reliable, account is that of the medical writer Thessalos, who in the 5th century BC wrote that the attackers discovered a secret water pipe leading into the city after it was broken by a horse's hoof.An "asclepiad" named Nebros, or, according to another version the Athenian Solon advised the allies to poison the water with hellebore.