Take out hover effect on product gallery overview

Hello, 

Whenever I hover over one image on the product gallery, another image appears. I understand it gives an overview but I prefer not to have it. I had set a thumbnail image but it didn't help. 

Here is my site, https://caterpillar-antelope-zbjy.squarespace.com/destination

password: ptphoto

Please help me remove the hover effect. I want but one image to appear as a hero shot.

Thank you!

Add to Home > Design > Custom CSS

.grid-image-wrapper.has-hover-img>img:first-child {
    opacity: 1 !important;
}
.grid-image-wrapper.has-hover-img>img:last-child {
    opacity: 0 !important;
}