Cross another bridge heading South to pick up a Star Piece.

Return to the pair of Cut trees and head off to the West to the hard-to-spot path.  Before traveling down it, though, check the dark area between the four trees to open up another grotto.  Most of what this hidden grotto holds is alternate versions of things you can already find- Keen Eye Skorupi, the even tougher Regenerator Tangela, similarly boosted Regenerator Foongus, and the bizarre and history-referential Flare Boost Drifloon, whose Special Attack is boosted when it has a Burn.  You can also find the odd Oblivious Spheal here.  Spheal is an Ice/Water pokemon that eventually becomes Walrein, whose hefty HP and defenses go a long way to offset the weaknesses of being an Ice-type, particularly given its competent Special Attack.  Unfortunately, the Spheal you find here has the Oblivious hidden Ability, which prevents it from being affected by Attract.  Compared to the alternatives of Thick Fat (takes half damage from Fire and Ice attacks) and the much more useful Ice Body (heals 1/16 of maximum health every turn as long as the weather is Hail), Oblivious is pretty much a waste of an Ability, sadly.

Exit the grotto and follow the small path South and West to find some more grass and a Pokemon Ranger.

Rotation Battle: PKMN Ranger Daryl (2340 Poke, Sitrus Berry)
Opponent: Nosepass Lv 39, Jolteon Lv 39, Galvantula Lv 39

From here you can head further West on the beach to a small house where a kid will give you a Power Lens, a very rare item indeed.  The Power Lens is part of a set of hold items that are used to boost a pokemon’s gains in Effort Value points.  If you want to know more about Effort Values, please check out the relevant article in the main Pokemon section, as that has an in-depth analysis of what Effort Values are, how they work, how they are gained, and why you should know about them.

Return to the Cut trees again and this time head into the grass to the right.  You’ll find a Pokemon Ranger running circles around a rock and a pair of Item Balls here- the one to the West is a Blue Shard, and the one to the North is a Max Ether, which will fully restore the PP of a single move for any pokemon you use it on.  The Ranger is running rings around the rock, so it’s pretty much inevitable that you’ll wind up battling her.

Triple Battle: PKMN Ranger Dianne (2340 Poke, Sitrus Berry)
Opponent: Vibrava Lv 39, Flareon Lv 39, Larvesta Lv 39