Davos brings his ship, Black Betha, up Blackwater Bay.
He thinks back to the strategy meeting: Davos suggested a more cautious approach with scouts checking things out first, but Ser Imry's plan calls for a knock-out blow; when Davos expressed his concern, he was given the old we'll get back to you on that treatment.
Ser Imry sounds the attack. As they sail forward, Davos notices a chain boom in the water and wonders why they did not raise it in defense.
The battle begins. Rocks, arrows, and spears rain down on Stannis's fleet, and Joffrey's tiny fleet engages them.
Davos orders ramming speed, as does his son's ship, and the two slam into Lady's Shame. The enemy ship falls to pieces.
Wildfire begins to fall upon the ships.
Fighting through, Davos and his crew board the White Hart and kill the crew, taking the ship.
Surveying the battle, Davos notices the Swordfish has caught aflame and is drifting toward a Lannister hulk, which is bleeding wildfire into the river.
Davos screams for a retreat as the ships collide. The explosion knocks Davos off the deck and into the bay.
As he's being swept down the current, he sees that the chain boom has been raised. Stannis's fleet is trapped in the wildfire hell of Blackwater Bay.