Outline, first pass:
Episode 4: Climb Every Mountain
Teaser: Frame - Arwen looks into the Mirror of Galadriel and witnesses her mother's rescue from the den of the orcs at the hands of her brothers?
Main - Elves journey across Middle Earth - sweeping vistas and awesome music! The Elves are singing as they traverse majestic terrain under starlight.
1. Disorganization in Teleri camp - no one knows the plans, everyone is doing their own thing, impossible to get the group to work together.
Elwë expresses frustration to Lenwë, urging him to get his people together.
2. Lenwë is organizing his 'lost tribes', but while journeying to and fro, he comes upon a walking tree. In wonder, he stops to investigate. The tree (actually Treebeard) makes some 'Hoom, hoom' noises, but fails to talk. After the first attempts at communication reveal that the creature is sentient, the elves are delighted. (There are multiple elves and ents present, including Treebeard's wife!)
3. Lenwë informs Elwë that moving now is out of the question. They've just met the tree-people and have to stay to learn to talk with them!
4. The rest of the Sindar press on, crossing the Misty Mountains. Elwë decides he better tell Finwë about this development, that he has 'lost' some of his people. He leaves Olwë in charge and sets out with Celeborn, Beleg (and Mablung?) to journey to the Noldor camp.
{Tom Bombadil cameo here?}
5. We catch up with the Vanyar, who are a small, organized group far ahead of the others. They reach the shores of the Sea, and are bewildered what to do next. Ossë has an 'aha!' moment and fetches the island that Melkor made when he was showing off his volcano skills last season. The very large island is brought near the shore, and we see the elves board the 'ferry.' The island leaves the bay.
6. In the Noldor camp, Elwë is happy to see his friend Finwë. One of the Noldor (Mahtan?) makes a disparaging remark about the disorganized, lagging behind Teleri - Finwë defends his friend. Elwë is also frustrated with his group, and wants to know how Finwë keeps the Noldor on task. The ingenious timekeeping device of the hourglass is revealed, and Finwë gifts one to Elwë to help. Elwë is none-to-pleased when he has to share Finwë's attention with Míriel, but their tension is mild.
*Halfway point*
7. On the return, the Teleri party is nearing the camp in Estolad when they reach the forest of Nan Elmoth. They hear nightingale singing. They approach a glade in the forest, but only Elwë can enter. The others are turned around and stumbling, confused, and unable to see what is in the glade. Elwë sees a beautiful woman and reaches out for her. Suddenly, she is beside him, and lays her hand in his. They both stop, frozen in time.
8. Elwë's party searches and calls for him, but to no avail. They decide they have to report back to Olwë (who is in the camp nearby). When Olwë hears the news, he is stricken, immediately assuming his brother is lost forever. He thinks this the work of the Dark Hunter. Celeborn speaks up, assuring him that this was *nothing* like the Hunter, and that there is still hope if they keep searching for Elwë. Olwë announces that those who wish to stay and search for Elwë are free to do so, but that the rest of them will soon be leaving to continue the journey (as Elwë would have wanted).
9. Angband update: Sauron visits the dungeons, and chastises Tevildo for his harsh methods. 'They're no good to me dead' type of complaints, and that Tevildo is pushing them too hard. Sauron show him how it is done, and brings an elf in for a 'good cop' interrogation. He wipes away the blood, tells him it doesn't have to be this way, and starts preaching the cult of Melkor. The elf is obviously terrified of Tevildo (who is prowling in the corner), but responds hesitantly to Sauron's overture.
10. The Nandor have succeeded in teaching speech to the ents! It's still slow going, and their communication is limited, but the entwives are in turn teaching the Nandor farming. Best inter-species collaboration ever!
11. Olwë leaves camp, and is dismayed that only half the Teleri are coming with him; the other half have chosen to remain behind in the camp and be part of the effort to search for Elwë. Círdan gives Olwë a bit of a pep talk.
12. Climax 1: The Noldor have arrived at the Bay and are waiting on the shore. Suddenly, the massive island returns! They are excited to see it, but Finwë is now upset, because the Teleri are nowhere in sight. He asks some of his companions if there has been any news, or if anyone knows where the Teleri camp is at present. There is no information. Mahtan(?) speaks some kind words about the Teleri, suggesting they will be along shortly. Reluctantly, Finwë agrees that it is time to go, and gives the order to board the island. As it sails away into the sea, he has a moment of doubt and panic, a premonition that he will never see Elwë again, and almost suggests stopping the island or going back to wait. Míriel reassures him.
13. Climax 2: We see the glade where Elwë and Melian are transfixed. The nightingales are still singing. We see a timelapse of the forest growing up around them.
Denouement: Frame - Arwen explains to Celeborn that knowing what happened doesn't give her the peace she thought it would - she still feels the same as she did before seeing the vision in the Mirror. She still misses her mother.
Worth pointing out that we've neglected the role of Oromë in this episode. Also, I have some concerns about logistics/geography. And the Frame might not work best as a bookend this time - we may need to interrupt somewhere else with Arwen, and end with Finwë and the final shot of Elwë and Melian in Nan Elmoth.
Nightingale song sounds like this: