The mind of Datis was necessarily very ill at ease. He dreaded the wrath of Darius; for despots are very prone to consider military failures as the worst of crimes. The expedition had not, however, been entirely a failure. Datis had conquered many of the Greek islands, and he had with him, on board his galleys, great numbers of prisoners, and a vast amount of plunder which he had obtained from them. Still, the greatest and most important of the objects which Darius had commissioned him to accomplish had been entirely defeated, and he felt, accordingly, no little anxiety in respect to the reception which he was to expect at Susa. One night he had a dream which greatly disturbed him. He awoke in the morning with an impression upon his mind, which he had derived from the dream, that some temple had been robbed by his soldiers in the course of his expedition, and that the sacrilegious booty which had been obtained was concealed somewhere in the fleet. He immediately ordered a careful search to be instituted, in which every ship was examined. At length they found, concealed in one of the galleys, a golden statue of Apollo. Datis inquired what city it had been taken from. They answered from Delium. Delium was on the coast of Attica, near the place where the Persians had landed, at the time of their advance on Marathon. Datis could not safely or conveniently go back there to restore it to its place. He determined, therefore, to deposit it at Delos for safe keeping, until it could be returned to its proper home.