Guinevere One

Guinevere One was a Human-built space probe sent to explore Mars for signs of life, but was abducted by the Sycorax spaceship before it reached its destination. The Sycorax utilised the A+ blood contained in the probe to use blood control to cause one third of all Earth's population to climb tall buildings and threatening to make them jump unless half the world was sold into slavery. (DW: The Christmas Invasion)