Interstellar. Titans of Ardana, #3

Martin Calder and his girlfriend Dana-no last name given-are back. Their powers are now known to the general public, and their wish is to help out those who need it. However, those in the law enforcement world aren't so accepting. Reduced to starring in their own reality show-and messing it up-other, more urgent matters take precedence. The weather has changed, and the sun has started to turn blue.
Although it's a physical impossibility, it has happened. The Earth will freeze in a matter of weeks if nothing is done, and only Martin and Dana can help. Their journey takes them back to Ardana, Dana's home world, in search for answers, and subsequent searches send them on a quest across the galaxy where they meet vampires, energy-sapping rays, cat-mole people, and a boy-not-a-boy who may be the answer to everyone's prayers.
Sometimes, giving everything isn't enough. Sometimes, you have to give more than that-even your life.