JQuery Show Class on hover issue

JQuery Show Class on hover issue

I am trying to get a div to show when a link is hovered.
There will be multiple classes too so only the nearest should show.
This is what I'm trying:
$(".box").hover(function() {
$('.overlay').closest.show();
});
<div class="event" id="selector">
<a class="box" href="#" title="">Event</a>
<div class="overlayOuter">
<div class="overlayInner"></div>
</div>
<div class="overlay" style="display:none;"> I will come out when class
Box is hovered </div>
</div>
When I hover class="box" then class="overlay" is shown.
The problem is that Overlay is not appearing so I'm guessing my jquery is
wrong?
How can I get this to work?