Operation: THRAWN was the UNSC Navy's plan for the naval defence of the Epsilon Eridani System as part of the larger WINTER CONTINGENCY in the event of a Covenant attack on the system. Though it was executed during the Covenant's invasion of the system in 2552, Admiral Roland Freemont rescinded the order when he realised the true size of the invading Covenant force, and redirected the forces involved to Earth.