Read the first story. It's the best one, a variation of a Lovecraft theme. Then stop.

The remaining tales are all the same. Just change the names and locations. Otherwise it's the same plot repeated ad infinitum:

1. Hero's friend is ridiculed for outlandish theory and goes away.
2. Years later hero hears from friend asking him to come to his remote location.
3. Upon arrival hero learns of friend's success with experiment, but unforseen consequences lead to a threat to mankind.
4. Hero & friend try to stop threat but are thwarted and imprisoned.
5. Friend tries again, succeeds in stopping threat but is killed in process and hero returns home alone.

It's an okay plot if you use it now and then, but not if it occurs in every story. You'd do much better to stick to his Legion of Super Heroes comic book stories from the 60s. ( )