In late 1805, two French frigates, supported by a Fleur-de-Nuit, launched a surprise attack on the HMS Allegiance. The Fleur-de-Nuit began dropping bombs on the Allegiance. Temeraire, who was alone on the dragondeck at the time, took flight and engaged by himself. The Allegiance's captain, Tom Riley, turned the ship broadside to engage, knowing the slow, heavy dragon transport had no hope of outrunning the frigates. French boarders, however, had arrived by small boat to attempt to take the ship.
It was a difficult fight for Temeraire, surprised and unarmed, as the Fleur had the advantage of its night vision and a fully battle-ready crew. Laurence's crew used flares to attempt to aid Temeraire by providing light that could blind the Fleur. As they were repacking a pepper-gun ball with flash powder, Chinese envoy Sun Kai arrived with fireworks, which provided more light than the flares. Harris was able to hit and wound the Fleur-de-Nuit; unfortunately, Harris was killed by a bomb dropped as the dragon fled.
Laurence managed to get aboard Temeraire while his officers and men helped engage the boarders. He refrained from pursuing the Fleur, and directed Temeraire toward the French ships, the true threat to the Allegiance, instead. Temeraire used the Divine Wind against one of them, and a wave that formed in his wake capsized the ship, Valerie, resulting in the loss of its entire complement of some 300 men.
Lily's formation, including Maximus, Dulcia, Messoria and Nitidus, were conducting night maneuvers near Brest with the British fleet when they saw the fireworks and came to assist. The French promptly surrendered. The second French frigate, Chanteuse, was taken as a prize.
Although the British prevailed, the losses were heavy, especially for Laurence's crew. Temeraire himself was injured. Among the officers, first lieutenant John Granby, second lieutenant Evans and midwingman Martin were wounded; Granby and Martin stayed with the Allegiance, but Evans's broken leg required him to return to England.
Among the crew, two of the topmen were wounded, bellman Miggsy was killed. Among the riflemen, Dunne was wounded and Donnell killed. Four harness-men were killed. Cadet Andrew Morgan, working with the harness-men, was also killed. To help replace the crew, Capt. Berkley left two of Laurence's former topmen, Portis and Macdonaugh, who had been reassigned to Maximus while Temeraire was grounded.
Granby's injury was to have further consequences, as he took a fever and was out of commission for quite a while. In the his absence and that of Evans, third lieutenant Ferris was left in charge of the crew. Quite young and not as experienced as Granby, he did not know how to convince the other aviators to take no notice of the jibes of the sailors. This led to an incident in which the armourer's mate Blythe struck naval midshipman Reynolds to prevent him from challenging Martin to a duel in which Martin could not engage. Blythe had to be severely flogged for striking an officer, which increased tensions between the aviators and the sailors.