Among the four Champions, Fleur Delacour was the least prepared. Hogwarts winters were exceptionally harsh, and the lake water was bitterly cold. After uncovering the Golden Egg's secret, she had not gone diving in the lake beforehand to gather information like the other Champions had. As a result, Fleur had badly underestimated the difficulty of the Second Task.
Though the Bubblehead Charm could indeed solve the problem of breathing underwater, Fleur ran into serious trouble as soon as she entered the lake. The icy water numbed her limbs, making her movements sluggish. Worse still, she had no idea where the mermen had taken Gabrielle, nor did she even know there was such a place as a Mermen Village.
However, her most precious little sister, Gabrielle, was still at the bottom of the lake. Even if Fleur regretted not making more preparations, it was already too late.
Fleur knew she had to snatch Gabrielle back from the mermen.
Enduring the discomfort caused by the freezing water, Fleur used both hands and feet to desperately swim toward the lakebed.
Before long, someone with a shark's head swiftly passed her. It was Krum; Fleur recognized his swimming trunks.
Of course, Harry and Albert were also wearing very distinctive clothes.
Harry Potter was no slower either, following Krum as he swam toward the depths of the lake.
There! Follow them.
They must know where the mermen took the hostages.
After all, Krum often went into the water even in cold weather. He could not possibly know nothing.
As though she had seized her last lifeline, Fleur desperately swam after them. However, even though she put every ounce of strength into swimming, the gap between them kept widening. In the end, Potter and Krum both vanished from sight.
Fleur encountered every difficulty Dumbledore had described