All the few runes under Rehvka's control within the force field exploded instantly, causing the entire tower to shake for a few minutes.
The elven heroine couldn't understand the reason behind that act from Rehvka. The elf had practically mastered ninety-eight percent of everything; destroying those few runes would indeed delay the time it would take for her to take control over everything again, as she would have to recreate those runes. However, the cost of that extra time was that now the elf could enter the force field and eliminate Rehvka's group easily, making no sense in the end. Little did she know that it also allowed Alm and Bruno to come out as well.
Going a little back in the past, the elf felt that something very strange, beyond her knowledge, was happening. Naturally, the reason for that was Bruno and Alm's arrival. It's just that the elf didn't know that at that time.