What are the elements of the plot of "A Sound of Thunder"?

The elements of plot are exposition, rising action, climax, falling action, and resolution. 

Exposition

The exposition of a story is where the basic premise is introduced.  We meet the characters, learn what the setting is, and find out the initial conflict.  The setting is important in this story.  The story takes place in the future, because time machines have been invented. 

Eckels felt his eyelids blink over his stare, and the sign burned in this...

The elements of plot are exposition, rising action, climax, falling action, and resolution. 

Exposition

The exposition of a story is where the basic premise is introduced.  We meet the characters, learn what the setting is, and find out the initial conflict.  The setting is important in this story.  The story takes place in the future, because time machines have been invented. 

Eckels felt his eyelids blink over his stare, and the sign burned in this momentary darkness:

TIME SAFARI, INC. SAFARIS TO ANY YEAR IN THE PAST.

YOU NAME THE ANIMAL. WE TAKE YOU THERE. YOU SHOOT IT.

Eckels is the protagonist.  He is the one who hires the time travel agency.  He is a big game hunter, and he is interested in hunting a dinosaur to get more of a challenge.  Travis is the severe safari guide, and the men are accompanied by his assistant, Lesperance, and two other hunters, Billings and Kramer.

The problem is that time travel is very dangerous.  If you make one misstep, you could change the entire future.  Eckels is told this, and he is also told that there is no guarantee he will return alive.

Rising Action

Rising action is the sequence of events leading to the climax.  The time machine lands, and Eckels is introduced to the path and pointed to the dinosaur.  He’s a big game hunter, right?  What could go wrong? 

Climax

The climax is the turning point.  Eckels freaks out.  He does not want to shoot.  He thinks that the dinosaur is too big and scary to go down.

“Why, why,” Eckels twitched his mouth. “It could reach up and grab the moon.”

“Sh!” Travis jerked angrily. “He hasn’t seen us yet.”

“It can’t be killed.” Eckels pronounced this verdict quietly, as if there could be no argument.

Travis shoots the dinosaur himself, telling Eckels to go back to the time machine.  He does so in a daze, accidentally walking the wrong way, off the path.

Falling Action

Falling action is the wrapping up of the plot.  Travis makes Eckels dig the bullets out of the T-Rex.  They can’t leave anything behind in the past.  Then they are getting ready to return and Lesperance asks Eckels if he wants a trophy picture with the dinosaur.  They have to leave the body behind.  This is when Travis realizes that Eckels stepped off the path earlier.

Resolution

Resolution is the ending.  The men return, and find the future altered.  There is a different man president, and the language on the sign is the same but the spelling is different.  Travis shoots Eckels.