To Wake the Dead by Richard Laymon

An ancient beauty . . .

Amara was one the Princess of Egypt, the beautiful wife of Mentuhotem the First. Now, 4000 years later, she and her coffin are merely prized exhibits of the Charles Ward museum. Her lovely face and strong, young body are no more. If you were to look at her today, you would see only a brittle bundle of bones and dried skin. But looks can be very deceiving. . . .

A missing mummy . . .

Barney, the museum's night watchman, is the first to make the shocking discovery that the mummy's coffin has been broken open. He immediately assumes it's the work of grave-robbers who care nothing about the sanctity of the dead. But Barney doesn't have a chance to do anything about it. Then two security guards come upon the open coffin and they too believe that the mummy has been stolen. What else could sane men think? By the time they realize the unbelievable truth, it's far too late for them to do anything . . . ever again.

The walking dead!

Now Amara is once again freed from the cramped confines of her coffin, free to walk the earth, free to stalk her prey. Free to kill. Nothing can satisfy her deadly bloodlust. And no one can stop her. You cannot kill what is already dead.