Sequel to Mechanic Hearts And Postage Stamps, Circuit and Adhesive now have a new son, how will this effect their lives? And how will their family come into play?

A grumpy stallion who hardly goes outside, a changeling hybrid mare with a temper, what happens when this grump falls in love with the mail stallion at his door?

A Look at what happens day to day in the rainbow factory, as told by the employees. suspense will follow!