1462: an alien who feasts on the suffering of sentient beings dines off the agonies of Vlad the Impaler's twenty-thousand victims near Targoviste, Romania.

1688: a woman is framed for witchcraft and hanged by the neck in Boston.

1965: a toy store that never seems to run out of special toys is suspected of being the location of a temporal portal, the same one used by the agony-feeding alien.

2022: a grandfather, showing his young grandchildren what remains of the Boston of his youth, is shown that portal by his granddaughters.

And they're off! Off through the gate that grants wishes, off to deal with time travel, off to break and enter, off to endure the pain of seeing afresh loved ones long since departed in their own time. They're off to deal with hardened, murderous criminals and with equally murderous aliens.

And all of that is set around the time of Christmas joy, in old, fine hotels, with presents, fresh loves, Handel's Messiah, a department store's enchanted village, old delicacies, modern weapons, lasers . . . and a very special calico cat.