After you escape from Dalton, you learn about a mysterious object known as the Time Egg.
Search for the Time Egg
Upgrade equipment from the Nu if necessary.
Then get in Epoch. Watch as the Ocean Palace becomes the Black Omen. The Black Omen is basically the final dungeon in the game, and I advise against trying it now. Besides, there are a bunch of side-quests to take care of, not the least of which is the one involving Crono.
So, once the cut-scene is over, press Y to get the time gauge.
REMEMBER: DON'T go to 1999 A.D. unless you want to fight Lavos now.
Instead, go to the End of Time.
Beat Lavos now for ending "Reunion"
Talk to the old man. At first he doesn't tell you much, but as the sad song is playing, start to leave (either go through the door to the pillars, head to the end of the Epoch dock thingy, or open Spekkio's door) and he'll call you back. Talk once more and he'll tell you something about Crono.
Now take Epoch and go to 2300 A.D. Fly on over to the Keeper's Dome (you should be right near it when you get there), and go through the door in the back, there will be a Magic Tab on the floor near the end of the passage. Talk to the Nu in there.
If you already got the Crono clone earlier in the game, you can skip the next few paragraphs.
Next, go to 1000 A.D. and fly to Leene's Square. You have to earn 40 Silver Points, so do that however you want to.
You can also fight Gato, west of Leene's Bell, and get 15 points each time you beat him. With your current levels, it should only take one hit to defeat him.
When you've gotten 40 (you can always check how much you have with the guy in the tent near Leene's Bell), go outside and save the game. You can get the clone for free, but it may take a few tries.
Go to Norstein Bekkler's lab and talk to him. If you lose the game, you'll have to shell out big bucks for the clone. So, just keep trying, loading the saved game if you screw up. In the end, you get the Crono clone.
Go to Crono's house, go upstairs, talk to his mother, and get the clone.
Now go back to 2300 A.D. to the Keeper's Dome and talk to the Nu. Now you're ready to challenge Death Peak, with the help of Poyozo Dolls. Switch off the Nu.
First run up, and the doll will be there. Talk to it quickly (so the wind doesn't blow you away), and the doll will turn into a tree. You won't be blown off the mountain as long as you stand directly south of the tree and don't press any buttons (right after talking to the doll is the only time you don't have to press any buttons to stay there).
To the right there's a Power Tab, get it. If you hurry you can get behind the tree again before the wind picks up.
To successfully stay behind the trees, you have to first run up to it, be DIRECTLY behind it (not a little to left or right) and then hold the up button. Wait for the wind to die down, then run up to the next tree and repeat the process until you get to the next screen above.
Go left, beat the Krakkers. Before heading up the ladder go left and get the chest. Then go back and up the ladder.
Head down the slope to the right, fight the Krakkers, then up the ladder. Exit right.
Beat or avoid these Krakkers, then head up. When the path splits, take the lower path first. Below is a hard-to-see save point, and a chest. Then go back up. Hug the left wall and go into the cave.
Do NOT hit the shell of this beast, or it'll hit you with a needle attack. Just use physical attacks on its head, and if anyone gets chaosed, Heal them at once so they don't accidentally hit the shell.
Open the chest and exit north. Follow the path, open the chest (BraveSword), then hug the right wall and exit south. Above you is a sparkle, check it to open a cave. Then head back the way you came, hugging the right wall to exit north, hugging the north wall to exit southwest, hugging the left wall outside, and saving down below if you want. Exit through the cave you just opened.
NOTE: DO NOT SELL the BraveSword. In a New Game +, the Masamune disappears from the inventory (since it's a storyline item), so you'll need the next most powerful sword for Frog.
Just walk slow if you want to avoid the Krakker that falls. Get the chest. Outside, fight the Lavos Spawn as you did before. Then exit left.
Talk to the doll. To get past here without falling, do this when you're on the narrow ledge: hit up as you walk. To go down, let go of up. To go up, run as you go up. To stay where you are, just hold up. Make your way left and to the next screen.
Across from the falling Krakkers is a chest, try to avoid them and get it, then run down to try to avoid more Krakkers. Exit south, and from here just follow the path.
Talk to the last doll, then climb down and fight the Lavos Spawn just like the last two. Just as the doll said, push the shell it leaves behind, up to where there's a piece of ladder you can't reach. Then press A next to the shell to climb up it, and go the rest of the way up the ladder. Get the chest to the right.
The Scene at Death Peak
You won't fight any more monsters on the way, and the next scene will be different depending on who's in your party.
I'll give you some hints about how the scenes differ, but I won't give them away.
There are four possible main scenes, for the four characters who can take charge on the peak. There are slight variations to each scene depending on who *doesn't* take charge.
If you have two or three of the following members in your party, then one of them will take charge. Here is the list of precedence that the characters take.
(Ayla and Magus never take charge, but may say some stuff)
Depending on what you like in terms of plot, some scenes are "better" than others. If you're on a console it's a little hard to try them all (although this of course is part of what gives the game such high replay value), but I'd say Marle's is the most interesting, followed by Lucca's. If I remember correctly, Robo's is boring, but Frog's is moreso.