The Detective Tales cover for February

I have decided to upload the monthly cover picture from Detective Tales early on. I thought about which one to upload since January, but nothing came to my mind until now. It was difficult to top the brilliant one I uploaded last year (from the February 1937 issue). Last month I chose a sober one, so this time I decided to go for something melodramatic. This is from the issue of February 1939. You have the (private eye?) hero punching square in the jaw a doctor/chemist holding a scalpel, while the damsel not so much in distress shoots at a mostly unseen gun holder. Another badguy, a doctor or a chemist, in any case probably a mad scientist, is holding a huge vial of chemicals (acid?) and is about to hurl it on the hero. The setting is a lab, they are maybe making some drugs there. Or maybe biochemical weapons. This could for a story bordering on the science-fiction genre. In any case, I love how filled with details this cover is.