It’s a zen koan for 2020, a spin on the parable of the tree falling in the forest: if your immune system speaks and no one understands what it’s saying, does it make a sound? The answer is yes. When in distress, the immune system rings proverbial alarm bells that are accompanied by warning messages that we need to decode.

In the 4th century BC, fresh from the heat of battle, his wounds and abrasions stinging and sore, Alexander, Prince of Macedon soaked in a warm tub dyed golden orange by the blood-red filaments of the saffron crocus. The tinted water, he knew, would clean his wounds and encourage healing while the heady aroma swirling around him soothed his weary mind.