One way that you could do this is to create a new segmentation in your lead database, dividing leads into Named and Unnamed.
"Named Leads." = Lead Attribute Email Address [is not empty]
Default = Everyone else (i.e., leads with email addresses)
Then when you're making your pages on the microsite, you can use this to segment the content. The persons who are recognized (cookied, and in the lead database with an email) can see the "real" page with the information, and the persons who are unrecognized (uncookied or not in the lead database with an email) can be shown a "give us your email for access to this!" form, then directed to the first stage.
This would provide your desired experience in which persons have to be cookied and named leads to access your microsite. If a cookied/named lead emails Chapter 2 to a coworker, the uncookied/unnamed coworker will only see the login form, then be directed to Chapter 1 upon completion of the form.
Hope this helps!
Best,
Edward UnthankSEO/Web Specialist
Yesler