UPPER BARROW
Amulet of Unyielding Will
I start off at #1 on the Upper Barrow map. I go north, fighting a few more Telthor Wolverines along the way.
At #2 I get ambushed by a LOT of Telthor animal spirits. Safiya helps blow them away with repeated castings of Empowered Firebrand spells.
The Ancient Wooden chest contains a Duskwood Bow (+6 Mighty), 99 Fire Arrows, and the Amulet of Unyielding Will (+5 natural armor class vs. Fey, immunity to Charm Person, immunity to Charm Monster, immunity to Charm Animal, immunity to Dominate Person, immunity to Dominate Monster). I don't have any use for it though.
Safiya's 18th Level
Safiya has earned enough to advance to her 18th level, so she learns the Chain Lightning and Firebrand spells. These spells will be important in some upcoming battles for her. She also picks up the Shield Proficiency feat, ultimately with a view towards having her equip the Shield of the Magi.
Shroud of the Leopard
I now travel towards the southeast corner, fighting more Telthor Badgers and Telthor Wolverines along the way. The Ancient Wooden Chest at #4 has a Sapphire, a Blue Diamond, and the Shroud of the Leopard (+5 leather armor, +8 Listen, +8 Spot, Greater Cat's Grace (11) 3 / day). I'll save the Blue Diamond for an item enchantment, while the Shroud of the Leopard will provide a decent interim armor for Gann once he joins the party.
Telthor Leg Bone
Now I travel towards the northeast corner, fighting a couple of Telthor Wolves along the way. A trap surrounds the bear skeleton at #4, which Valeria disarms. The Ancient Wooden Chest contains a Hide Armor +4 as well as the Telthor Leg Bone (Club +4, Ethereal Jaunt (13) 1/day). I hold onto to this so that it will become an interim weapon for Gann when he joins the party.
Trust of the Red Wizard
I then make my way towards the center of the map, just south of the large northern cave. Safiya has a 'moment' for lack of a better way of putting it. I deliberately choose the dialogue option that will win influence with her. I then engage in another dialogue simply to present some background information about who sent her to the Barrow and why.
The end result is that Safiya acquires the Trust of the Red Wizard feat, which as far as I can tell has two benefits. One is that she gains a +2 bonus to Concentration. The other is that her Empower Spell feat gets replaced with the Improved Empower Spell feat, which allows her to memorize damaging spells that will do x1.5 damage but at only one higher spell-level. Safiya is thus posed to become a powerful damage caster in her own right.
The video concludes with Safiya reconfiguring her spells to relfect her acquisition of the Improved Empower Spell feat: Empowered Polar Ray as a 9th level spell, Empowered Disintegrates, Empowered Firebrands, Empowered Chain Lightnings, etc.
Escape the Barrow
I buffed up beforehand, Premonition for Safiya, Greater Stoneskin and Extended Heroism and Persistent Blade Weave for Valeria, etc. I then go on ahead to #5. One thing is for certain, the spirit of Okku the Bear God will want to kill me. I let him close in while Valeria and Safiya cast Extended Greater Invisiblity on themselves. Valeria follows up an Empowered Mirror Images.
Safiya drills Okku with an Empowered Polar Ray and an Empowered Disintegrate, and quickly forces him to dissipate. By that time several Telthor animal spirits close in around me. That's when Valeria and Safiya let loose with multiple castings of Empowered Firebrand and Chain Lightning spells. The strategy suffices to soften up the rest of the Telthor spirits or kill them outright.
Okku will leave behind a Pristine Power Essence. An ancient wooden chest north of Okku's skeleton has the Axe of the Bear-King (Greataxe +4, +1d6 electrical damage, keen).
The spot at #6 marks the exit to the Mulsantir Gate.