Two worlds. One missing dad. Zero chance this sleepover at Grandpa's will be normal. Jack Flynn's dad isn't dead. He's just... missing. At least, that's what the Army says. But when a funeral goes sideways and a mysterious stranger on a motorcycle roars into their lives, Jack and his twin sister, Macy, are pulled into something way bigger than they expected. That stranger? Their grandfather, Ace-a washed-up, semi-pro wrestler with a wild past and one colossal secret; he's a Sentinel-protector of a hidden gateway to a forgotten realm called Oldenworld. And their dad? He didn't die in battle. He vanished through a tear in time-and only Ace knows why. From a time-portal hidden in Ace's basement to a shimmering staircase made of frozen light, Jack and Macy are hurled into a breathtaking adventure. But Oldenworld isn't like the history books-it's a land cursed with dark magic, a power-mad king, and secrets never meant to be unearthed. As mysteries unravel and enemies close in, the twins discover their family's legacy runs deeper than they ever imagines. Can they survive the dangers of time-travel and bring their father home, or will they become lost in Oldenworld forever? --Back cover.