"Wanna go see what's happening on the monster island?"

"Sure."

The monster island:

Contains monsters. Those gooey jelly things, chu-chus, limited threat, are probably the most common kind.

The twins have something of a grudge against the jelly things.

The jelly things don't have sufficient intelligence to detect a grudge. They do occasionally drop hardened, thick chunks of goo. Concentrated chu jelly.

At least the twins brought a bag this time.

There are also weird helicopter-hat monsters, more boko babas, thorny vines that sprout out of nowhere and try to block their path, and giant mosquito things that release dozens of small spiky critters that try to jump onto them and attach to them. Probably not a good idea to wade through here too recklessly. Their deku leaves are great at tossing around most of these monsters with gusts of wind, though.

Anything resembling treasure?

Sure! Batches of rupees - the local money - here and there, a crusty old map of the place in one chest. They probably don't manage to explore the whole place in a couple of hours though.

Yes-besides, the twins want to discuss something with Deku.

Deku is patiently minding the forest. As usual for the last half dozen decades.

"Hi Deku!"

"Hello, my little not-vampires."

"How's being a tree today?"

"The forest is healthy. Summer's coming. It's a good day."

"Anything interesting happening?"

"Makar's trying a new song."

"Ooh, where is he?"

"Down by the sea stacks on east side. Said he felt like watching the sea today. Have fun if you're goin' to see him."

They do so.

Makar is, indeed, trying a new song on his violin. It's slower and more thoughtful compared to his usual fast and cheerful tunes.

The twins start dancing to it. The vampiric grace is mostly intact.

He falters a few times. Or pauses and makes 'hmm' noises. New songs are an experiment.

...However, the pauses and falters do manage to make them slip from their rhythm. 

"I can do my usual songs instead if you guys want? I got this one in a song book Hollo ordered, is all."