Only Richard Sharpe could get caught up in a fleet battle on the way home from India and find romance on a Royal Navy line-of-battle ship. But he does, and it's a highly entertaining read, if a little dark and implausible in places. Bernard Cornwell had to stretch things a bit to explain what an army officer was doing at a sea battle, and although Sharpe has always had a brutal way with bad guys, he is particularly ruthless with a minor villain in this book.
"Sharpe's Trafalgar" is set after the conclusion of the prequel trilogy of novels set in India, in which he obtained a fabulous treasure, was promoted to be an officer after saving the life of General Wellesley (the future Duke of Wellington), and dealt with the traitor Dodd. Shipping home to join the 95th Rifles, Sharpe initially takes passage on an East Indiaman, and finds an old opponent as one of the passengers. Treachery follows and the ship is captured by the French.
However, as the story is about Sharpe's Trafalgar, we know that he will not remain a prisoner of war for long. Sure enough, after an involved series of events, including the obligatory rescue of a lady in distress, Sharpe and his fellow passengers find themselves guests on a Royal Navy 74 gun ship of the line, chasing a French battleship half-way round the world. Until both ships arrive off Cape Trafalgar on 21st October 1805 ...
As usual Bernard Cornwell has done a great deal of research so that the Napoleonic era battles he describe seem real, and in the historical note at the end he explains that many of the events described during the battle of Trafalgar were based on things which really happened.
The next novel after this in the chronological sequence is "
Sharpe's Prey," the main action of which is set two years later in 1807 when Napoleon's continental blockade results in war between Britain and Denmark. That book also tells you what happens to Sharpe's relationship with Lady Grace, the heroine of "Sharpe's Trafalgar".
If you liked the other Sharpe books, there is an excellent chance that you will like this one.