At the end of One Step Behind, Tamala turns the tables and traps you in the Elderwood Beast's Lair. Unable to leave through the cave entrance and blocked from fast traveling out thanks to Tamala., you must make it through the infected vines to find another way out. This is how to complete Like a Shiprunt in Palia.
Palia | Like a Shiprunt Quest Walkthrough
Once Tamala leaves the cave, you'll need to figure a way through the door that previously remained locked. Read the book that's to the right of the desk. It explains how to repeal the negative aura using the basin found in the lair. Fill the basin with water using your Watering Can.

You'll have a small amount of Flow infuse with you. A timer will appear under your name and Focus bar that shows how long this will last. While active, go to the door and open it. Behind it there are infected vines, what was actually repelling you from the door. Use your Axe to chop them down. Repeat the process at the water basin for any infected vines you find.
The next room is an extension of the camp you encountered in One Step Behind. It has five rummage piles for you to search through. There's a trap door out, but it's locked. The rummage pile containing the key is located behind the broken pot surrounded by a row of other pots. These rummage piles require you to use your Hoe to get the loot.

Once you have the key, head through the trapdoor down in to the Hidden Cave. This is when you get your first glimpse of the kid Nai'o mentioned. He's trapped by the infected vines with no way out. Fill the basin and chop down the vines to the left. Chopping the vines to the right takes you into a loop that leads nowhere.
Head down the left passage, but only go down the first slope. When you stop sliding, immediately go to the right. If you go down the second slope you'll end up in that loop and go right back where you started. Follow the path until you see a small hole to the left. There's another water basin in the distance as well as a climbing area to to the left.

Again, you're confronted with a fork in the path. Like before, chopping the vines on the right leads you to a loop where you have to climb out using the climbing wall. The left vines bring you closer to freedom and the trapped Umbraan boy. Go down the slope and continue to follow the path to the right. Going over the ledge to the left brings you to the climbing wall.
Unlike before, you want to chop the vines to the right. The left vines and the opening bring you down to a dead end and a new climbing wall. Follow the path, which becomes more littered with ancient debris as you go. The next section has a single way forward, but leads you into a maze. To make it through the maze, follow the path lit by the red luminescent flowers.

This leads you right to the trapped boy. Use the water basin to the right to bless yourself and hack through the vines holding him captive. Before you speak with him, grab the treasure chest near the drain grate to the left of the room. It contains the Cooking recipe for Bean Burger, as well as a Treasure Chest decor item.
Speak with the boy to launch into the dialogue portion of the quest. When Subira shows up he scampers off, proving that he's extremely skittish like Nai'o said. You're able to leave the cave and finish talking with Subira in the fresh air outside. She'll give you an Enchanting Runestone, necessary when crafting Relics. You'll also earn 20 Renown for completing Like a Shiprunt.
The next quest, Something Wicked, populates to your log immediately. You don't need to start it right away, but finishing it does net you a new store and a unique reward.