Foreshadowing in a sound of ⚡️

"We guarantee nothing" 

The sound of thunder is a brilliant use of foreshadowing.
Foreshadowing is a technique used to hint at what is going to happen later in the story. 
The title of the the story foreshadows the last line of the story. The story has one sound of thunder the t-Rex roaring but at the end of the story it changes because the sound of thunder ends up being the gun shot that killed Eckles. 
The sign at the start of the story foreshadows that at the end of the story that the sign changes. At the start of the story the sign for the place to go back in Time is TIME SAFARI, INC.

SAFARIS TO ANY YEAR IN THE PAST.YOU NAME THE ANIMAL.WE TAKE YOU THERE. YOU SHOOT IT this then changes to TYME SEFARI INC. SEFARIS TU ANY YEER EN THE PAST. YU NAIM THE ANIMALL. WEE TAEK YU THAIR YU SHOOT ITT which foreshadows that they changed the present.

"We guarantee nothing" is a way of foreshadowing because it saying  the have nothing to save people for. This is foreshadowing because at the end of the story Eckles dies because of travis shooting him because he killed a butterfly. Eckles asked if they guarantee anything and they said no and he dies at the end of the story. The writer of the sound  of thunder uses foreshadowing in a way that doesn't reveal it self immediatley.