In 1935, beleaguered Bournemouth mother Louisa Durrell decides to uproot her family and build a new life on the sun-drenched island of Corfu. However, with money problems and four unruly children to care for, even a new start might not be enough to banish her troubles.

Larry falls dangerously ill, and it falls to Theo and his neighbour Sven to put their rudimentary medical skills to the task of saving his life. The family's money worries continue, but Spiros brings them good news from a surprising source. Gerry adds to his growing menagerie, while Margo is emotionally wounded - but gets little sympathy from Leslie.

Leslie falls in with a bad crowd and ends up being falsely accused of armed robbery, prompting Louisa to take desperate measures to save him. Margo takes a shine to a gardener at the Villa Mavrodaki, Captain Creech returns, and the family realises the extent of Gerry's passion for animals when he turns his bedroom into a centre for scientific learning.

The family faces the unwanted arrival of a domineering aunt, while Larry's girlfriend also pays a visit - giving the unwelcome relative an opportunity to voice her disapproval of the whole family. Sven makes an offer that helps Louisa cope with adversity and Margo falls in love - but Gerry is more concerned with his newly acquired owlets.

The family prepares for a celebration, and Margo is determined to persuade the reclusive Countess Mavrodaki to attend. Sven is put to the test by his potential family, but seems to make a good impression. Gerry begins to question whether keeping animals in his personal zoo is fair, and considers releasing them into the wild.