The Happy Return, like any start in a Long-Running Book Series, has some Early Installment Weirdness regarding characterization and one piece of it is that Hornblower is much more prone to ill-temper than in the later entries. However, while conversing with Lady Barbara, we learn that he had a son and daughter who died of smallpox but it's not made clear how long ago it was. The later-written book Hornblower and the Atropos ends with Hornblower coming home to find his children in the first stage of sickness, but he had also been told by his admiral that he was ready for a ship of the line and the Lydia specifically is in need of a captain. In other words, it hasn't even been a year since he lost his children.
Fridge Brilliance: A recurring character in the TV Series is Captain 'Black' Charlie Hammond, a highly distinguished Irish Royal Navy officer. He first appears as one of the examination board assessing for Hornblower for promotion to Lieutenant. Halfway through the examination the port is attacked by a fireship and Hammond witnesses Horatio climbing on the fireship to steer it away for the British ships, and for this act of courage recommends with the other examiners that Hornblower be made Lieutenant despite his poor performance in the exam. The next time we see him though, is as one of the judges at Hornblower's court-martial in the the two-parter 'Mutiny' and 'Retribution.' There he makes it clear his priority is to reach a verdict which protects the reputation of the Ax-Crazy / Shell-Shocked Veteran Captain Sawyer, who Hornblower had helped remove from command. Hammond quickly singles out Hornblower as his desired scapegoat, and goes out of way to interpret everything Hornblower did in the story in the worst possible light, even though we see in the Flashbacks that Hornblower's actions repeatedly saved the ship from disaster. The motivation seems clear enough and sets up Hammond as the antagonist for the courtroom scenes, but why would he pick on Hornblower, who it must be clear to a man of his experience is one of the most outstanding officers in the Royal Navy, when he could instead shift blame on to the clearly incompetent Lieutenant Buckland, or the dying Lieutenant Kennedy? They serve just as well if not better as scapegoats and keep the highly talented Hornblower in the service. This bothered me until I saw the most recent Hornblower episodes, when it is revealed that Hammond is actually an Irish Nationalist, who has been working as The Mole in the Royal Navy for years! Of course he had recognised the value of Hornblower to the British cause, and so was taking the opportunity at the court martial to deprive the enemy of one of its very best men, who had and would continue to be a thorn in the side of Britain's enemies, and who ultimately foiled Hammond's plans in the final episode!