There were several dark holes, or tunnels, within the lake. 

People were naturally afraid of darkness. Plus, none of them knew what lay within those tunnels, so Kang Oh's party steered clear of them.

However, the Lighthouse Turtle began to slowly swim towards one of them. 

Since Kang Oh's party was following it, they'd have to enter the hole too. 

Kang Oh unhesitatingly entered the hole, disappearing into the darkness.

Eder also entered the hole rather easily.

'Mm.' Sephiro briefly hesitated, but he couldn't stay here. His companions had already gone inside.

He gritted his teeth, went 'Screw it.', and swam inside.

Sephiro entered the hole and was soon consumed by darkness.

* * *

A dim light glowed in the darkness.  

That's why it was called the 'Lighthouse' Turtle! It was because its shell radiated a gentle light. 

The Lighthouse Turtle's light was so weak that it'd normally be unseeable, but it was so dark inside that it actually made all the difference. 

That dim light gave Sephiro a sense of ease, making him less frightful than before. 

'A Lighthouse Turtle, huh. What good naming sense...