In 446 BC, a more dangerous uprising erupted. Euboea and Megara revolted. Pericles crossed over to Euboea with his troops, but was forced to return when the Spartan army invaded Attica. Through bribery and negotiations, Pericles defused the imminent threat, and the Spartans returned home. When Pericles was later audited for the handling of public money, an expenditure of 10 talents was not sufficiently justified, since the official documents just referred that the money was spent for a "very serious purpose". Nonetheless, the "serious purpose" (namely the bribery) was so obvious to the auditors that they approved the expenditure without official meddling and without even investigating the mystery.