The Keep rises in the distance. That's your destination. However, you must first pass through some farmland that has been recently overtaken by the Wargar.
Upon reaching the farmhouse, watch the front door. Two armored Wargar Guardians kick through it and attack. In this situation, it may be best to break off and deal with the Wargar individually. Teaming up on one of the Wargar leaves one to move around the periphery and make uncontested strikes. Because these Wargar are so heavily armored, arrows don't do much damage.
Lure one of the Wargar away (especially if you're Caddoc) and then engage in melee combat. Roll away from the Wargar and look for openings in its defenses. One of the biggest exploits is when the Wargar goes for a heavy attack. It rears back and then lunges forward. Roll to one side and then rise up next to it or behind it, then land two melee strikes—or one heavy strike—before the Wargar recovers. If you attack head-on, the Wargar just lifts its shield and deflects your blow.
After defeating the armored brutes, look in the barn off to the left. A prisoner is tied to the rafters. Shoot him down. He murmurs something about trinkets; speaking of which, shatter the weapons racks by the barn and open the treasure chest.
When you enter the farmhouse, break open the two canisters on the ground floor for vials and then head into the backyard to locate a Deathstone body. He babbles about chickens. Go back inside, head upstairs, and watch for the walls to splinter against the ax of another armored Wargar. Take this brute down the same way as the two downstairs, rolling aside to dodge the heavy blows and then counterattacking before the monster recovers its momentum.
Following the fight, drop out the back of the farmhouse. More Wargar storm out of the cornfields. The carved path is narrow, which funnels them right into your hands. Take them out with splash-damage magic (Brimstone works well here) or cut them apart with arrows until they escape the corn. Finish off the first group with melee attacks and then enter the cornfield, hacking through the next Wargar.
When you enter the cornfield, keep an eye on the ground to the left. When you see flattened corn, cut through the still-standing stalks. This reveals a secret side area. Smash open the canisters for vials and then check to see if the gear on the ground is better than any in your inventory. A second secret cornfield area with similar rewards lies hidden on the right side just before you leave the fields.
Fight your way out of the cornfield and to the outer gate of the Keep. More Wargar Guardians attempt to stop your approach, but the same system of dodging incoming attacks and then launching your own as they recover works well. These brutes are vulnerable to magic, so if you can spare the mana, unleash a little magical hell.
Upon passing through the outer gate of the Keep, you discover another Seraphine portal for upgrading magic. Your first major monster battle is not too far ahead, so it's beneficial to upgrade magic that lets you fight from afar. After all, keeping your distance means your enemy cannot smash you with a melee attack. Upgrading E'lara's arrows is a good move, too, as she can use them against the beast that guards the Keep.