Hetty Feather and her little brother Gideon are forced to leave their 'borrowed' family and return to the Foundling Hospital, which fearsome Matron rules with an iron fist.

It's Hetty and Gideon's borrowed birthday but how can Hetty celebrate with her brother when girls are not even allowed to mix with the boys?

Mathias is back and a shadow of his former fearless self. With the hospital on lockdown in order to mass-produce toys that are supposedly earmarked for charity, the children start falling ill.

Matron's sister arrives to deliver bad news about her mother. Hetty's feisty little borrowed sister Eliza arrives at the hospital and, like Hetty, clashes with Matron.

Kindly nurse Winterson is sacked by Matron so Hetty convinces the children to go on strike. Will Matron capitulate before the choir debut their new anthem in order to win a £100 donation for the school's organ?

Hetty and Sheila are forced to work together in the infirmary. The boys compete in a series of gruelling army tests in order to win a place as a drummer boy in the army.

A distraught couple come to the hospital to reclaim their child. Gideon plans on escaping in search of his parents, but Vince and Judd have other plans.

It is open day at the hospital, and Matron tasks Hetty with looking after Lord Upton's snooty daughter Charlotte. Matron has plans to send Hetty to India as Charlotte's maid.

When Hetty finally escapes from the hospital, Matron goes on the warpath and thinks she knows where to find her. The gang try to expose Matron's true intentions behind Hetty's planned trip to India.