Bob Davidson retired from 22 SAS into an occupation he believed would be a contrast to the constant threat of death he had experienced in the Regiment. The dawn was breaking around the zoo, as head keeper he knew it would be the busiest, and usually hottest day of the year. All was quiet until a strange object fell to earth obliterating the wildebeests.The day began normally until the animals began to act strangely towards the now crowded visitors. Soon he had gathered a small band of survivors and became embroiled in a fight for survival as the animals, led by the Bengal tiger seemed determined to eliminate all humans. Police and his old comrades from the SAS arrived and tried desperately to reach him and his small band.The animals showed incredible intelligence and seemed to be working together in their quest.