Technically 3.5 stars, but worthy of the rounding up.
Sometimes experimenting with space rocks isn't exactly the smarted thing a scientist can do, especially when it's your first day on the job and you're just getting used to your laboratory. Dr Arthur Covington's first day on the job in an underground research facility does not go as he had planned. His experiment goes drastically wrong and an explosion occurs, but even the explosion is not typical. The dead come back to life and what happens next is best left to the conspiracy theorists.
The characters in Contaminated confused me, at times, as there were so many of them. There was one group sent to help get the survivors out of the facility and to safety, but not really, they were sent in by the head evil doer (we don't learn much about him in book 1) to eliminate the survivors and get Dr Covington out. Another group truly is sent in to help get the group out and then you have the actual group of survivors who are trying to get themselves to safety. No one knows who to trust. With constant threats around them from the undead, other humans and various traps set to keep people in and out, the multiple groups have quite a long haul out of the facility. All this, topped with the knowledge that they have a limited amount of clean air in their suits and are unsure of how safe the air above ground is to breath.
If you like a tale of constant threats lurking around every corner(and we're not just the undead version) and if you enjoy a keep you guessing and on your toes conspiracy, then definitely give Contaminated a try. It will be well worth your time and money.