The Lionguard were able to track down the final two suspects in the nick of time, so I headed their way. Astorra was tucked away in Caledon Forest and was immediately defensive of her actions. She quickly surrendered her side of the tale, citing manipulation. I didn't get the impression that she was responsible, but...naive. Trembling Song was the most helpful (and seemed at least somewhat remorseful). She was quick to share, sparing no detail, which shed light on the others' stories. During her journey to Lion's Arch, she was beckoned to join a group of travelers and sit by their fire. She believes that while she slept, they tampered with her offering to the effigy. Much like the other suspects, whatever was added to their offerings may have caused the chemical reaction that triggered the explosion. With the suspects headed to Lion's Arch, we're one step closer to the truth.