A tall, dark and handsome leader who's travelled in the TARDIS with the Doctor, but doesn't like to talk about it much;
A creepy bisexual second-in-command whose hobbies include dating his coworkers and pulling guns on his superior officers;
A likeable blokish sort whose function is to crack wise and make the tea;
A generally goodhearted and pretty but dim girl who wandered in on the whole setup and got adopted into it;
A frumpy girl who says practically nothing aside from occasional bits of expository dialogue and has no personality whatsoever;
...and that's all I'm saying. Let's just hope Benton doesn't have an Invasion cyberman tied up in the basement or anything.