In Assassin's Creed Valhalla, you may come across Rigsogur Fragments, which are a type of collectibles in the game. On this page of the guide, you will learn where to find the collectible and how to reach it. This will make it easier for you to max out the Lincolnscire region.
The ninth page of the saga can be found in Grimsby.
The saga is located in the building, on the bottom floor. You will get to it by destroying the boards that block the rear entrance. You shouldn't be bothered by any opponents while exploring - obtaining the treasure will be easy.