Gray Keep held the throat of the northern passes. Until that gate fell, no trade road could be used and no new allies could be reached. For three weeks, Vikings of Yggdrasil struck the stone walls and withdrew.
Every morning, when the mist lifted, Bjorn stared at the same place: the north tower. "Not even one stone is missing," he muttered. "We won't break this fortress with a hammer. We'll break it with wit."
That night Astrid left camp in silence. A black raven, Hrafn, rested on her shoulder. She had trained the bird since childhood. She tied a narrow leather strip to its leg with one line written on it.
"Come at dawn tomorrow. The gates will be left open."
No one believed it. Ragnar laughed. "Trust a bird and move an entire army?" Astrid stared into the flames. "Sometimes one raven outweighs a hundred axes."
Before dawn, heavy fog rolled in. The clan advanced without a sound. Bjorn led the front, Helga held the right flank, Ragnar guarded the rear line. A hundred steps from the keep, the iron gate truly stood ajar.
Inside, one guard hated the keep's cruel commander. After receiving Astrid's message, he deliberately broke the watch chain. Yggdrasil warriors slipped through the narrow entrance. By the time the alarm sounded in the courtyard, it was too late.
The battle was short and sharp. Ragnar secured the stairhead, Helga scattered the archers, and Bjorn marched straight toward the command hall. When the sun touched the walls, a new banner flew over Gray Keep.
That day Astrid was given the name Raven Mother, and the clan learned its first great lesson: victory is won not only by strength, but by patience and mind.