What's a quick and dirty way to get "lapsed" members in WordPress configured with s2Member?

What's a quick and dirty way to get "lapsed" members in WordPress
configured with s2Member?

I have a default installation of WordPress configured with the membership
management plugin known as s2Member. What is a quick and dirty way to
return an array of "lapsed" members?
I assume this information is hidden somewhere in the user's metadata.