An entertaining read, and as reviewers have pointed out, similar to stories by Robin Cook and Michael Crichton and worthy of the comparison. It reminded me a little of `Coma', maybe because of the sympathetic character of Dr Lasseter. I felt both she and Ryan were well drawn. His crisis of faith gave added depth and believability.
I did feel the story shifted focus a touch as it developed. From centring on Main and McKirrop it switched to Lafferty and Sarah. Not that this detracted from the tale but it did cause a moment's loss of direction for the reader.
Main's fate wasn't fully tied up as might suggested by, "he could see his son, Simon but something was dreadfully wrong...this wasn't heaven...it was hell." This does suggest we will learn the nature of this hell from his p.o.v. but we don't. Everything was explained but this felt untidy.
I also felt a shade uncomfortable at Sarah using her feminine wiles with Tyndall so willingly. It did seem out of character.
The only other bump in my reading road was at the finish. The final action felt a shade like reportage, and of course it is necessary to wrap up fast once all is revealed, but the ending paragraphs did feel a touch curt.
All minor complaints in a good read that carries you along nicely. Recommended.
Typos were few, but there. And of course Jameson is Irish and therefore whiskey and not whisky, Ken. Sláinte.