Managing the Hydra

Had the book not been technically adequate, one could have said that the authors have tried to bite off more than they can chew

In Greek and Roman mythology there is a big monster called Hydra which has many heads. For every head chopped off, it grows two. 

But a very small real version also actually exists which is of interest to biologists because of this regenerative ability. This fresh water organism does not appear to die of old age, or even grow old. This is the sense I took away from this book. One of its authors is a good friend; the other I have not met. 

Had the book not been technically adequate, one could have said that the authors have tried