The solution of the title has a double meaning. One is Joel and Rita's way out of the dilemma regarding Blake, and the other is their means of doing it - liquid poison that Rita can slip into Blake's food and drink, effectively killing him.
Michael Praed shot a scene for the episode that was later cut (he doesn't appear in this one as a consequence). All the remnants of the Moldavian plotline were being slowly taken out of the show as they were proving unpopular with viewers, with Praed and Joel Fabiani being the main casualties.
This was the least watched episode of the season.