Nick of Time by Ted Bell was one of those books that the kids begged for more of. You've got to check your reality meter at the door, but then you're in for a rip-roaring adventure tale wrapped up in a little bit of history. It's got time travel, pirates, battles, and heroism.
Initially set just before WWII, Nick McIver is living on a quiet little island where he doesn't think anything ever happens. Then he finds out his father is a spy for Winston Churchill and his ancestor sends him a time machine and asks for Nick to come to the past and help him. Intrigue and excitement follow for Nick and his sister, and for everyone reading along.
One of the things really enjoyed about the book was the relationship between Nick and his sister. Absent was the sarcasm, sibling rivalry, and me-first attitudes so prevalent in current novels featuring siblings. Nick is protective, chivalrous, and gentle with Kate. So, while the topic stretched the imagination, it also spoke to my kids about loyalty, bravery, true heroism, and caring for those who are weaker than you are.