Passing current page to summary.html

I’m listing the posts in the same Series in single.html by using the code below. It works like it should. Yet, now I need to add a class name to each post if it’s equal to the one being displayed at the moment.

So far I have tried using $.Scratch to set the value and pass it to the .Render summary but that doesn’t seem to work. What would be the right approach?

    {{ if .Params.series }}
    <section id="category-list">
    <h3>Chapters</h3>

    <div class="mini-posts">
    {{ $name := index .Params.series 0 }}
    {{ $name_url := $name | urlize }}
    {{ $series := index .Site.Taxonomies.series $name }}

    {{ range $series.Pages }}
    {{ .Render "summary" }}
    {{end}}
    </div>
    </section>
    {{end}}