Gisacum Ruins
The Gisacum Ruins are located in Evresin. It’s actually just northeast of Evreux.
This place has roughly half a dozen soldiers. After taking them out, look for a small door with the Hidden Ones/Assassins symbol. Eivor should be able to open it.
In the underground chamber, watch out for several rat swarms. Here, you’ll find a Tungsten Ingot, an opal, and the Gisacum Ruins key (which is on a desk in a faraway corner).
Before you leave, you can bring the explosive jars from one end all the way to the opposite wall. Just place them down while slashing at the rats since they’ll make Eivor drop the explosive when they start biting. When the coast is clear, carry the jar and throw it at the wall. Then, bring a second jar and use it to destroy another breakable wall. Inside is a Book of Knowledge that grants the Plague of Rats ability or its upgrade.
Anyway, let’s go to the next part of our Assassin’s Creed Valhalla: The Siege of Paris Hidden Ones Bureau guide to finally unlock the main chamber in Paris.
