Last time he held a contest, just over two months ago, Our Hero took a beating.

The challenge didn’t last two hours. People were all over him with answers. Obviously, he underestimated his audience. He’ll try not to make that mistake again.

Before going further: if you are in possession of, or have access to, an Advance Reading Copy of 50 Canadians Who Changed the World, then you are not eligible to participate. On your honour, now. A signed copy of that ARC is the grand prize, duly mailed to your home, and if you already have a reasonable facsimile, perhaps unsigned, sorry, you are out of luck.

This time around, we are going to give you seven chapter headings. Your mission, should you choose to accept it, is to name the world-changer in question. All are born after 1900 — i.e. in the 20th century. Yes, we are looking at a collective portrait of cutting-edge Canada. And, no, we are not giving away easy answers.

Now, the book is divided into six parts: Activists, Visionaries, Artists (Painters, Writers, & Filmmakers), Humanitarians, Performers (Actors, Musicians, & Athletes), and Scientists & Inventors. Each part has at least one representative. The chapter headings, in random disorder, are:

1. A feisty animal lover champions the natural world

2. An immigrant geneticist battles rare diseases

3. A Japanese Canadian clears the way for minorities

4. A law reformer brings war criminals to justice.

5. A globe-trotting doctor does her work in war zones

6. A Picasso of song refines self-expression

7. A cyber-guru hails the arrival of digital collaboration

To enter, simply click on the Comments link below and submit your answers. To win, you must identify all seven Canadians correctly. One entry per person. Contest deadline: August 15, 2013. No answers will be posted before that date. If more than one person submits a winning entry, a tie-breaker will be staged. It’s true: this time out, we are playing HARDBALL.