Historians from GCHQ are appealing for the veteran codebreakers of Bletchley Park to volunteer for one last act of service for their country: cracking the D-Day carrier pigeon cipher that has stumped Britain's finest minds. The coded message had been carefully filed in a small red capsule and attached to a carrier pigeon to be delivered 70 years ago. But instead of arriving safely at its destination, the unfortunate bird got stuck in a chimney en-route and lost. The message was found earlier this month by homeowner David Martin, who ripped out a fireplace to find the skeleton while renovating...