A Discovery Disappears - Christie and Agatha's Detective Agency, Book 1 (Unabridged)

Book 1 in the Christie and Agatha's Detective Agency series!
"Whoever gave you that sandwich did it deliberately. They wanted to sabotage Fleming's research."
When Agatha accidentally eats a major scientific discovery (hidden in a sandwich!), it's a race against time for twins Agatha and Christie to find out who's trying to ruin physician Sir Alexander Fleming's reputation.