To the original question - no, you should not punish the players.
By all means, however, you should use the consequences of their failure as a springboard for further challenging adventures. This thread has provided some great discussion in that regard.
Ultimately, the players (as opposed to their characters) will hopefully look back on this failure, not with regret, but with fond memories of the great adventure it lead into. Practically, there is no reason the players even need to know it was intended and expected they prevent the summoning, rather than being intended and expected they would fail, with the adventure continuing with their efforts to mitigate the damage and ultimately force the creature back to the pit from whence it came. Sometimes, failure is more fun than success!
As a GM, I find it very satisfying, when matters are going badly for the PC's, to hear a player say "Guys, I think this is one of those fights we were never intended to win". I've heard that several times from my players (probably about equally split between battles they were, and were not, expected to win). I consider it a great compliment that the players trust me to use their losses and failures to enhance the game, rather than end it. Even more so when I read posts from players who would rather have their characters commit suicide than be captured by the enemy.
In my experience, a game is enriched greatly when the players trust that the GM is not acting as their opponent, but as the designer of an exciting and challenging plot for their enjoyment.
By all means, however, you should use the consequences of their failure as a springboard for further challenging adventures. This thread has provided some great discussion in that regard.
Ultimately, the players (as opposed to their characters) will hopefully look back on this failure, not with regret, but with fond memories of the great adventure it lead into. Practically, there is no reason the players even need to know it was intended and expected they prevent the summoning, rather than being intended and expected they would fail, with the adventure continuing with their efforts to mitigate the damage and ultimately force the creature back to the pit from whence it came. Sometimes, failure is more fun than success!
As a GM, I find it very satisfying, when matters are going badly for the PC's, to hear a player say "Guys, I think this is one of those fights we were never intended to win". I've heard that several times from my players (probably about equally split between battles they were, and were not, expected to win). I consider it a great compliment that the players trust me to use their losses and failures to enhance the game, rather than end it. Even more so when I read posts from players who would rather have their characters commit suicide than be captured by the enemy.
In my experience, a game is enriched greatly when the players trust that the GM is not acting as their opponent, but as the designer of an exciting and challenging plot for their enjoyment.