Front and centre, soldier! You're part of UNIT now, the Unified Intelligence Taskforce. We are the Earth's best defence against the myriad alien forces who would try to subjugate and conquer our planet.It's not an easy job, and even those recruited for their scientific knowledge can find themselves on the front lines of combat against almost unstoppable foes. We will protect humanity from extraterrestrial terrors or die trying.Defending the Earth is a 160 page full color sourcebook for the Doctor Who: Adventures in Time and Space roleplaying game. Within, you'll will find: The history of UNIT Rules for creating UNIT characters, including new Traits and Areas of Expertise Expanded firearms and combat rules, including mass combat and skirmish rules Details on major UNIT personnel, including the legendary Brigadier Lethbridge-Stewart Two new adventures