The family are surprised to find out that Leslie has three different girlfriends, so Louisa decides to take it upon herself to help him pick one by having each member of the family invite their favourite girl to afternoon tea. Larry injures his leg and Theo decides to use his newly set-up x-ray unit to try and examine it. Elsewhere, Gerry continues to grow his animal collection, Margo takes up a job as Theo's assistant, and Aunt Hermione arrives in Corfu for good.
Louisa and Larry receive the devastating news that Aunt Hermione has died in her sleep. As the family make arrangements to have her body sent back to England, Margo gets to work on organising a memorial service. Leslie decides that he wants to be with Dionisia, and prepares to let Daphne down gently - however, it turns out that she is pregnant with his child, and her father is determined that they must get married as soon as possible. Gerry becomes fascinated by a wall in the back garden that is covered in insects.
Larry and Louisa return to England. While his mother is reunited with her cousins, Larry returns to London, where he falls in with a group of Bohemian artists - including writer Henry Miller. Back in Corfu, Leslie gets offered a job as a policeman, Gerry saves a donkey from an abusive farmer, and Spiro forbids Margo from seeing Zoltan.
Larry goes to Athens on a shirt trip, and returns with a royal guest. Louisa is delighted to have a prince staying under her roof, but soon finds herself with a less welcome visitor in the shape of Captain Creech. Tension is soon stirred up between the two houseguests when Gerry sits an interview for a local school, and the prince and the captain voice very different opinions on the subject of education.
Spiros spends time with a glamorous Italian family who have recently arrived on the island. Louisa is jealous of the attention he is paying their new neighbours and invites the new neighbours over to learn more about them. She ends up convinced they are hiding something, while Margo feels threatened by their eldest daughter. Larry joins the fire service, and Gerry falls in love.
The family plan a party to celebrate Gerry's 13th birthday, but when a plague of mosquitoes descends, they are forced to hold it inside.
As the party planning progresses, Louisa is finding it hard to accept that her youngest is growing up. Gerry insists that he doesn't want a fuss, but gets frustrated and upset when the party is clearly aimed at someone much younger.
Trying to pick up the mood, Margo's transformation of an otherwise disastrous party results in hilarious antics as everyone but Spiros seems to join the party spirit. His distant behaviour concerns Louisa who wonders why he has locked himself in a room to sing sad love songs.
Henry Miller comes to stay with the family, and stirs up tension among Louisa and her children with his strange behaviour and the controversial content of his books. Sven is arrested after the government announces a crackdown on what it considers 'immoral behaviour', and Larry rushes to his aid, acquiring books on fascism and miscarriages of justice from the countess to help him take matters into his own hands. Spiros continues to pine for his wife, and Louisa is torn between her feelings for him and need to ease his pain.
The family meets members of a travelling circus, and gets involved in helping them to drum up business. Larry falls in love with a contortionist, while Margo takes to the ring in person to perform a very dangerous act. Gerry is more concerned with making sure all of the animals featured in the show are well-treated. Spiros cannot bring himself to return to his empty house and begins spending more and more time at the Durrells' home - but the magic of the circus brings him and Louisa closer together.