YA book about time travelling by mixing chemicals in specific amounts and then traveling to given locations. Spoilers.

[Walter]

Read this book circa 2015 to 2018, though quite unsure of this.

Unfortunately I don't remember the plot, though it might involve the protagonist trying to find their parents who were either lost or kidnapped.

It took place on an Earth where specific points were like these rifts in time and if you drunk a potion/chemical (it was more science fiction than magic, though the actual term used I don't recall) then stepped into these locations you would time travel, with when you went dependent on the specific percentage of what chemicals are in the mixture.

I think there was a scene where someone made fun of the boy protagonist for not wanting to board a ship without their mom, but someone else chided them and remarked it was more likely because he had to leap like 20 feet to get onto the ship.

!!!!!!!!!!!!!!!MAJOR SPOILERS BELOW





Near the end of the book the two protagonists, the boy and a girl, are on a ship being piloted by the bad guys. The girl reveals that she's actually related to them (possibly their niece?)

The ship is going somewhen unknown, but it's very far back in time and way before any period the girl had gone. The potion that enables time travel they gave her to drink made her nauseus.

The boy offers to stay on the ship, but the girl states that it's pointless because the potion he has is different to what she had and he's not going to end up in the same time as her if/when they go through.