This is a story with a young seventeen year old girl as the principal character. It is one in the series of four. Jan Torridon has to try to keep things going whilst her father is ill in Glasgow hospital. Her home is in Kilmodan, probably on the coast of Argyll, and remote from any places of large population. The family consists of Mr Torridon, eldest son Torquil who is about to go to University to train to be a doctor, Jan aged seventeen and young Ivor (about 14). Jan loves sailing and the family's yacht which is called Cormorant.
The illness of Commander Torridon throws the three children into turmoil and they soon discover that they have to face a huge financial problem. Chartering the Cormorant is one way of meeting their debts. However, this takes Torquil off the scene for the first two weeks. Meanwhile Jan is left to deal with the business that Ivor has drummed up by rashly placing advertisements which offer the facilities of a sailing training school. The first two customers are two rather ill-matched American cousins called Ruth and Lucilla. All that Lucilla appears to be interested in is making an impression with the opposite sex. Ruth is lame and seems to be very much the poor relation in her family.
Over a short period of time Jan finds that she has developed a real liking for Ruth and they work their way towards a very strong friendship. Meanwhile Ivor tries to play his part in the arrangement by teaching the remaining pupils how to sail the dinghies.
Jan finds that she has to cope with her fiery and irresponsible younger brother, with the cooking and cleaning chores, with the financial arrangements and the chilling background presence of her father's business partner who now wants his money back. Torquil returns from his cruise in the Cormorant and the family finds that things are likely to get worse for them. Jan also finds that Torquil believes she has not looked after the budget in the way that he could approve. It almost seems like she has made things worse whilst being desperately unhappy at the same time.
Lucilla's attraction to Torquil is an irritating factor and a short voyage to give everyone a break turns everything into a crisis when the weather starts to put all the sailors both amateur and experienced under pressure. The destination is a small island called Eileen Dubh where a run ashore proves to be a mixed blessing. On the return to Kilmodan the storm draws closer Lucilla is knocked overboard and Jan is the one who plunges in to the rescue. Torquil and Ivor complete the recovery but the whole group are forced to endure a good deal of discomfort on Cormorant and spend the night riding out the storm in the lee of another small island called Eileen Mor.
Two episodes dominate the end of the book. One is the severe illness of Lucilla and her slow recovery from a pneumonia like condition. This forms a new bond between Lucilla and Ruth and between Ruth and Lucilla's parents. Meanwhile Torquil is forced to sell Cormorant in order to pay back Bingham, his father's partner. Though he avoids having to sacrifice the boat directly to Bingham and makes a deal with the man who originally charted the boat and whom he likes, for Jan the fact remains that her beloved Cormorant has to go. A further surprise lies in wait in the last few pages of the book.
The next book in the series, Torridons' Surprise uses many of the same characters but Jan is forced out her Kilmodan world into a new situation that shows another side to her character. The Scottish location of the book is somewhat clarified when we find that two of the major characters complete their marital arrangements by a wedding in the town of Oban.