The implied warning is: Get yourself killed in the wilderness!
The Nightmare Sea Monster has devoured a substantial amount of Soul Dreamlands, it probably knows about the existence of the Fishing Party, and with the depletion of its origin strength due to the Mark of Nightmare, its power is only at the middle-stage leadership. Therefore, it's particularly cautious.
Yet, it doesn't want to leave the delectable food that is marked with consumed origin energy.
Therefore, it went into hiding, preparing to observe for a while, waiting for the moment when Gary Smith lowers his guard to swallow him.
During this period, Gary Smith actually had the opportunity to escape, but he couldn't, considering that although his soul could escape, his solidified Dreamland couldn't.
If he left, his soul would be severely damaged as it got chewed up by the Nightmare Sea Monster that regains its senses, which would then continue its pursuit.
"Escape is just a slow death!"
