Thrice Upon a Time

SOS FROM A FUTURE THAT WILL NEVER BEIt's amazing enough when Murdoch Ross's brilliant grandfather invents a machine that can send messages to itself in the past or the future. But when signals begin to arrive without being sent, Murdoch realizes that every action he takes changes the future that would have been...and that the world he lives in has already been altered!Then a new message arrives from the future: The world is doomed!