After Ned's unfortunate ascension to Warden of the north, things started moving rather quickly. Army's were mobilized, and Hinrik found himself once again preparing to be plunged into war.
Jon Arryn had wanted Hinrik to stay in the Vale, as even if he was quite skilled, he was still only a boy of 13. However Hinrik would not hear of it and demanded that he be allowed to come. Some may have considered it childish, but Jon knew how serious his son was when he wanted to be, so with quite a bit of grumbling.
Both father and son set off to raise the banners of the Vale, while Ned and Robert returned to their homelands to do the same.
The basic plan they had come up with, was for each of them to secure their own lands first, putting down any loyalist lords before taking their forces to Riverun to see if they could sway Hoster Tully and the Riverlands to their cause. Without the Riverland's support all of them knew that they simply wouldn't have the numbers to win this rebellion. Since both the North and the Vale simply weren't as populated as the other regions of Westeros, save perhaps Dorne.
Honestly, Hinrik was quite tired of war and all the scheming that came with it, having already lived through 3 of them in his past life, but he had always been foolishly loyal, so despite the fact that he could escape the violence with a word to his father, he couldn't bring himself to abandon the people he had grown close to in this life.
As He made his own calculations, Hinrik was sure Ned would have the easiest time rousing his lords, they were already frothing with rage at the death of their beloved lord. Robert on the other hand, Hinrik expected to take a bit longer as the Baratheon's hold on the storm lands was no where near as fanatical as the Stark's.
Hinrik himself was fairly confident that they would find rousing the vale nearly as easy as rousing the North, and was happy to see that he was right, there were very few houses in the vale that would chose to side against his father, who had long proven to be a good and wise ruler. Nonetheless it was nice to see confirmation of the respect and loyalty everyone held for his family.
There were however, a handful of houses that "remained loyal to the king" and so it was necessary that those unruly lords be brought to heel, before the Vale could truly go to war.
It was perhaps a good thing that Hinrik had this chance to show that he could be a reliable commander, before the truly dangerous fighting began, and gave his over anxious father an excuse to keep him away from the fighting.
An unexpected, though not unwelcome opertunity these skirmishes provided him with, was a chance to get closer with his cousin, and only other close family member, Denys Arryn. Both of them were eager to prove themselves, if for slightly different reasons. Due to their eagerness to be in the thick of the fighting, they spent much of the short campaign through the Vale in each others company.
With his cousin at his side they were able to accomplish any task they were given quite handily. They cut through the enemy lines with little resistance, especially with the help of his new spear.
That was another upside of his choice to go to war, his father had gifted him a new blade. Apparently house Arryn was in possession of a Valerian steel dagger, won long ago in some forgotten battle, and his father had chosen to have the dagger reforged for his son into a spearhead. So as to give him every available advantage.
It wasn't quite his unbreakable Adamantine staff but Hinrik was rather taken with his new spear. The rippling of the blade was quite interesting, and Hinrik's style of fighting became just that much more deadly, now that he was once again confident in the superiority of his weapon.