Fortress wall

The engineers had built a stone fortress with an iron portcullis, guard towers, scorpion ballistae, water cannons, and no doubt many other nasty surprises for the defenders to use.

Frank laughed. “Yeah, well... it’s harder than it sounds. We have to get past those scorpions and water cannons on the walls, fight through the inside of the fortress, find the banners, and defeat the guards, all while protecting our own banners and troops from capture. And our cohort is in competition with the other two attacking cohorts…

The cannon exploded in a starburst of blue, green, and white. Defenders screamed as a watery shock wave flattened them against the battlements.
Kids toppled over the walls but were snatched by giant eagles and carried to safety. Then the entire eastern wall shuddered as the explosion backed up through the pipelines. One after another, the water cannons on the battlements exploded. The scorpions’ fires were doused.
Defenders scattered in confusion or were tossed through the air, giving the rescue eagles quite a workout. At the main gates, the Fifth Cohort forgot about their formation. Mystified, they lowered their shields and stared at the chaos.

Frank shot his arrow. It streaked upward, carrying its glittering rope. When it reached the top, the metal point fractured into a dozen lines that lashed out and wrapped around anything they could find — parts of the wall, a scorpion, a broken water cannon, and a couple of defending campers, who yelped and found themselves slammed against the battlements as anchors. From the main rope, handholds extended at two-foot intervals, making a ladder.
“Go!” Frank said.
Percy grinned. “You first, Frank. This is your party.”
Frank hesitated. Then he slung his bow on his back and began to climb. He was halfway up before the defenders recovered their senses enough to sound the alarm.
Frank glanced back at Fifth Cohort’s main group. They were staring up at him, dumbfounded.
“Well?” Frank screamed. “Attack!”
Gwen was the first to unfreeze. She grinned and repeated the order. A cheer went up from the battlefield. Hannibal the elephant trumpeted with happiness, but Frank couldn’t afford to watch. He clambered to the top of the wall, where three defenders were trying to hack down his rope ladder.
One good thing about being big, clumsy, and clad in metakFrank was like a heavily armored bowling ball. He launched himself at the defenders, and they toppled like pins. Frank got to his feet. He took command of the battlements, sweeping his pilum back and forth and knocking down defenders. Some shot arrows. Some tried to get under his guard with their swords, but Frank felt unstoppable. Then Hazel appeared next to him, swinging her big cavalry sword like she was born for battle.
Percy leaped onto the wall and raised Riptide.
“Fun,” he said.

SoN ch.11