Translation of 我想会吗? - I thought, is it possible?
B: 嗯。我想，会吗？他可能已经在暗中做安排了吧。


First, this is a transcription of colloquial dialog, which means the lines can be fragmented and is not entirely grammatical.

Second, I can see how it can be ambiguous and misleading due to the punctuation. Actually, 他可能已经在暗中做安排了吧 is also a part of the 'thinking'. It could have been clearer if it had been punctuated this way:


  B: 嗯。我想：“会吗？他可能已经在暗中做安排了吧。”


Which makes the meaning obvious:


  B: Yes. I was thinking, is it possible that some arrangements had been done by him already, in secret.