Bolero (Bolero #1)

A new series from two bright-eyed and bushy-tailed little scamps! A woman running away from a broken heart discovers a mother-key into parallel universes.

The rules are:
• The key can work on any door.
• The mother will only let you visit 53 universes.
• Do not ask to speak to the mother.
• Never hop more than 53 times.