The MYSTERY OF THE GOLD COIN (Greetings from somewhere)

The MYSTERY OF THE GOLD COIN (Greetings from somewhere) vol. 1 series by Harper Paris.

When Ethan and Ella Briar learn that they are moving away from their hometown of Brookeston, they are not happy. Then the day before they are set to move, something strange happens. An ancient gold coin that the twins grandpa Harry gave Ethan suddenly goes missing! Will Ethan and Ella find the coin before it's time to head to the airport? And will they realize that moving might not be so bad? That maybe, just maybe, it means an exciting new adventure?

it is published by - Simon & Schuster