When Sam's father disappears, Sam uses a strange carved stone and a coin to go find him.

Ten days ago, Sam's father disappeared. It wasn't all that unusual — he was an eccentric antique bookstore owner, and sometimes left for days, searching for a special book for one of his customers. That was one reason why Sam was living with his grandmother for a while. His father just couldn't be depended on.

On Sam's birthday, after his plans had been canceled, Sam decided to go to the store and look around and see if he could figure out where his father was, and when he would be back. But when he went to the little apartment over the bookstore, Sam discovered that all his father's clothes, shoes, and even his toothbrush were there.

Had something happened to him? Was he lying dead somewhere? Sam looked around the store, and even went into the basement, which was used as a storage room. He had only been down there once or twice, but it looked smaller than before. There was a tapestry hanging on the back wall that Sam hadn't seen before, and when he looked behind it, he found a wall and a door leading to a small, hidden room. 

The hidden room contained a small lamp, a cot, a table, a book about the crimes of someone called Vlad Tepes, who lived in the 1500s, a small coin, and near it a big carved stone, shaped like a keyhole with a rounded top. The top was carved like a sun, with six slits that looked like rays, and in the bottom a small cavity had been hollowed out. Sam tried fitting the coin into the slits, but it fell out. But when he tried fitting it into the center of the sun, it stayed there, held be some invisible force, and the stone began to vibrate and hum. Sam reached out to touch it, and felt his body catch on fire.

The next thing he knew, he was on his hands and knees, vomiting into the grass. He wasn't in the basement anymore, but where was he? It turned out he was on a small island off the coast of Ireland, in the middle of a Viking attack. He escaped, and found another stone and another coin, like the ones he'd found in the basement, and suddenly, he was in France during World War I, and then in ancient Egypt, then somewhere in Europe. And in each place, there was a stone and a coin to take him to the next place, but none of them took him home. 

Is this what happened to his father? Are they both lost in time? Will they ever be able to find their ways home again?