King Harald had sent Egil to observe and discover the weaknesses of the defenses.
The attack on Kattegat begins with most of the invading forces attacking from the front trying to break through the defenses and enter the city.
Egil and some of his forces come later when almost all of the defenders are protecting the "gates" of Kattegat.
Lagertha realizes that and tells Astrid and that they are in the wrong place , then she goes back with some forces to strike the forces coming by water. Later Lagertha appears alone in front of Egil and his men with a torch on her hand , some of the warriors charge on Lagertha and she drops the torch on the ground were there was some kind of oil, burning the warriors alive. All of the warriors behind Egil started running away , only he stays behind, he charges on to kill Lagertha but is pierced by Astrid's spear during the attempt. Unfortunately Torvi is injured during the battle.