8. Two lines. No season. Link to the previous verse, but break away from any particular season. This can be tough, since sometimes words that we don't think of as seasonal are seasonal—at least in some people's minds—like kite-flying (New Year's), mist (spring), flies (summer), moon (autumn), and fireplace (winter).
If you're new to renku or have any doubts about a particular word, check an online guide (search keywords: haiku, season words, kigo).