How will the readResolve() method of the proxy class get called in the Serialization Proxy pattern?

How will the readResolve() method of the proxy class get called in the
Serialization Proxy pattern?

I am studying up on Serialization Proxy pattern. It basically says to have
a a proxy class that should be declared as a static nested class of the
enclosing class that we want to serialize. So the basic idea is that the
proxy shields the enclosing serializable class from perils of
Serialization.
However the implementation isn't actually clear to me . Why do we call the
writeReplace() on the outer class and the readResolve() on the proxy
class? Since the proxy class is like a static member of the outer class
how will it even get serialized? If it does not get serialized then how
will the readResolve() be called on the proxy during deserialization?
I am sure I am missing something basic here. Can someone shed some light?