Sweeping the Shelf

Mobs are not in the cave. They are above it, on Lighting Ledge. Twilight Stormcallers / Howling Rifdweller are in the same area, so that's easy to do.

You will be able to see the Lightning Channel sparkle, loot it - and you have your Charged Condensed Jar (for the quest called Lighting in a Bottle).

BY THE NORDRASSIL'S RIVER Quest Tree From Whiterock

N)Hero's Call: Mount Hyjal!(A) N)Warchief's Command: Mount Hyjal!(H)
 ├──────────────────────────────┘
G)As Hyjal Burns 1)The Earth Rises 	1)Inciting the Elements
 |					1)Flames from Above
2)Protect the World Tree──┐
2)The Flameseer's Staff  2)War on the Twilight's Hammer
2)Flamebreaker			
2)The Return of Baron Geddon	N)This Can Mean Only One Thing...
3)Emerald Allies		9)To the Chamber of Inceneration!
3)The Captured Scout		9)What is This Place?
3)Twilight Captivity		9)The Twilight Forge
3)Return to Alysra		 ├>9)Do My Eyes Deceive Me?
3)A Prisoner of Interest	9)Ascendant Lord Obsidius
3)Through the Dream
1)Return to Nordrassil───────┬>Wings Over Mount Hyjal*
4)The Return of the Ancients ├>Scrambling for Eggs*
 ├>Save the Wee Animals*     └>The Wormwing Problem*
 ├>Disrupting the Rituals*
 ├>Fighting Fire With ... Anything*
 ├>If You're Not Against Us...*
 ├>4)In the Rear With the Gear  6)Gar'gol's Gotta Go
 |				6)Get Me Outta Here!
 ├──────────────────────────┐
4)End of the Supply Line   4)Harrying the Hunters
5)The Voice of Goldrinn(A) 5)The Voice of Lo'Gosh(H)
5)Goldrinn's Ferocity(A)   5)Howling Mad(H)
 ├──────────────────────────┴──────────┐
 ├>6)From the Mouth of Madness        6)The Eye of Twilight
 | 6)Free Your Mind, the Rest Follows 6)Mastering Puppets
 ├>5)Lycanthoth the Corruptor{H}      6)Elementary!
 | G)The Shrine Reclaimed{H}          5)Return to Duskwhisper
 | /
6)Cleaning House{H}───────>7)Sweeping the Shelf{H}
7)Lightning in a Bottle{H}
8)Into the Maw!{A2;H;H2}

8)Forged of Shadow and Flame
 |
 | 8)Crushing the Cores 8)Rage of the Wolf Ancient
 ├──┴────────────────────┘
8)Cindermaul, the Portal Master
8)Forgemaster Pyrendius
8)Return from the Firelands{H}──>The Last Living Lorekeeper*
 ├────────────────────┐
Aviana's Legacy*  The Fires of Mount Hyjal*
Quest zones:
1)Nordrassil_____2)The Verdant Thicket_____3)Hyjal Barrow Dens+Ruins of Lar'donir_____4)Wolf's Run_____5)Shrine of Goldrinn_____6)Gar'gol's Hovel_____7)Lightning Ledge_____8)Firelands Forgeworks_____9)Blackrock Caverns
N)Not-needed_____G)Gluing Separate Questlines
*Click to see more info about that quest-line.

IMPORTANT INFO:

1. 
   
2. End of the Supply Line and Harrying the Hunters can be done by both factions, but "The Voice of..." followup requrement is different.
3. 
   
4. Goldrinn's Ferocity and Howling Mad allows other players to share you quests next on line, but Lycanthoth the Corruptor{H} will let you be in same phase as npc.
5. 
   
6. Into the Maw!{A2;H;H2}. There are 2Alliance and 2Horde variants, for each faction one from wolf spirit and one backup from main quest guy in Shrine of Goldrinn.
7. 
   
8. Whole Firelands Forgeworks(8) chain doesn't have any pre-quests. You can get first time to Hyjal and ask warlock to summon you there and do the quests. However Lightning in a Bottle{H} is needed to use the standart teleport.
9. 
   

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A better formatted one

The Shrine Reclaimed (go talk to Ian Duran nearby)

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• Cleaning House (kill 8 ogres)
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  • Sweeping the Shelf (kill 13 twilights)
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  • Lightning in a Bottle (collect an object)
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    • Into the Maw! (from Spirit of Goldrinn, Step through the flamegate)
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    • Into the Maw! (from Ian Duran, Step through the flamegate)
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