Er'cana and Ahnonay are two Ages that were both written by Kadish. Before embarking on your journey through these two ages, better read some more on this guy. Both Er'cana and Ahnonay would be mere meaningless puzzles without the backstory of Kadish and his desire to be revered as the Grower. He was a guildmaster in the time the D'ni lived in the caverns. He was rich too. His treasures are even today, still piled up in Kadish Tolesa's vault.
To find out more about Kadish and the Grower, read the DRC notebook that you can find in the Watcher's Sanctuary or Pub. The notebook is next to the linking book to both Er'cana and Ahnonay. The Watcher's Sanctuary can be visited via the Nexus. (The Nexus refers to it as Watcher's Pub.) On the upper level of the Watcher's Sanctuary you'll find a small room with a closed door and 5 books that are referred to as "Words". These books contain the prophesies that were written down by the Watcher. Most of it seems to make no sence, although you could occasionally recognize events from the previous Myst games. More importantly, one of the first paragraphs on the first page of the first book describes some of the things that the Grower is supposed to do. The second book on the second page tells us of even more things that he is supposed to do. This will become important later.
The Grower was prophesised to be an important person in D'ni history and future. In myst 5, we learn about Yeesha's story of her becoming the Grower. From Myst 5 we know that she is the Grower and that means Kadish is not. Yet, Kadish wanted the other D'ni to believe that he was the Grower. The Ages Er'cana and Ahnonay were written specifically for that single purpose: convince the other D'ni that he was the Grower.
The linking book to Er'cana can be found in the Watchers Pub, on the lower level on the left side of the DRC notebook. When you link to Er'cana you appear in a tunnel or cave. Go forward and find your first Relto page at the end of the tunnel. This Relto page adds these large mushrooms to your Relto. Turn around and go in the other direction out of the tunnel.
When you exit the tunnel, you see some sort of elevated railway tracks running through a valley or rather a dried up riverbed. Around you are some large mushroom/fungi like bushes and some smaller bushes. Boy, these D'ni had a thing for mushrooms, like in Teledahn, Eder Kemo and here again...
Turn left and walk to where an opening in the right side wall reveals another set of tracks. Walk towards these other tracks and follow it to the right. You will come across a chasm that you cannot cross. Behind the track support is a Sparkey though.
Turn around and follow the tracks in the other direction. Just past the point where both tracks are visible through the opening in the wall, a cave entrance shows up on the right side of the path. Enter the cave, at the end you'll find a cloth on the wall (*). The symbol on the cloth resembles a shell and these cloths are therefore also referred to as shellcloth. Touch it and behind you appears part of a symbol in the air. This symbol will grow with each cloth you touch. There are 7 cloths in each Age, so still 6 to go.
*In the Deep Island Shard and the UAM Shard you will find no shellcloth on the wall here. Instead, they have a starfissure carved in the wall that links you to a bahro cave. There are only two shellcloths in the riverbed area (where you are now), while MOUL has four shellcloths in this area. That means that the Deep Island Shard and the UAM Shard have only five shellcloths in Er'cana. However, these Shards do have a sixth cloth inside the great tree in the Watcher's Sanctuary.
Walk out of the cave and towards the closest track support. On the back or right side of it is the second cloth. After you touched it the symbol in the cave has grown a little bit. Now follow the tracks all the way to the end. You'll face a large facility but it appears to have no entrance. There's not much you can do here now except touching a third cloth in the middle of the front-side of the facility.
Turn your back towards the facility and follow the tracks on the right side back to where you started this Age. While running back, pay close attention to the small bushes as they appear at a certain distance from you out of thin air...
Halfway back you could go see the cave with the symbol in it. If you do, you will see that it has grown another bit. This will continue until all 7 cloths have been touched.
When you're back at the starting point in front of the first cave entrance, continue walking forward in the direction we have not been to yet. Around the corner a large train or machine sits on the track. Behind it is a large round metal door or someting that looks like a large train bumper. Walk until you reach this metal door. On the right side you will find a fourth cloth so touch it and walk towards the train or machine on top of the tracks. See those two large metal arms on the sides of the train? It looks like the train is actually a harvester for these mushrooms presumably.
Locate the ladder on one side of the harvester and climb it to get onto the harvester. Walk to the left, around the corner you will find the controls of the harvester. One lever on each side and one lever in the middle. Push the middle lever to the forward position. Then pull the right lever. The walkways between the front cart and the harvester retract and the harvester starts to move forward. Enjoy the ride while the harvester moves towards the facility.
Glitch Alert:Sometimes when you climb onto the harvester the camera moves away towards the facility. Whenever that happens, your avatar is warped to the unloading area in the facility where the cart is raised. If you climb up or down the ladder there, your avatar will fall down and panic-link back to Relto. It's as if the game would rather skip the ride on the harvester and warps your avatar to the facility without the harvester. There's also a variation of this glitch where the camera moves towards the facility and back to the harvester without warping your avatar to the facility. In these cases you can simply try again as it does not always happen. Although I have not tested this, I think that making your KI visible in the top left of the screen will also prevent this glitch from happening.
* End of Part 1 * Next: Er'cana Part 2: Facility