Two people in a Beijing restaurant intentionally laced eggplant dishes with enough of a blood pressure drug to send 80 diners to the hospital. Everyone recovered, but 34 of them had to have their blood pumped to remove the drug.

According to a recent report in the Annals of Internal Medicine sum by Michaeleen Doucleff  of NPR,  the two perpetrators were in cahoots with the restaurant down the street, and they wanted to give it a “competitive advantage” by sickening their rivals’ diners.

Such competitive poisoning is not unheard of in China. Just last year, The AP reported on a local dairy farmer who intentionally tainted his competitor’s milk supply with nitrite.

In the eggplant incident, the miscreants hid the drug clonidine – a white, odorless powder – in the restaurant’s starch. When the chefs thickened up the braised eggplant with the starch, they inadvertently served up a few nearly toxic stir-fries.

All diners that ate eggplant for lunch on April 23, 2010, fell sick almost immediately, the report says. They got dizzy and tired, suffered from nausea and blurred vision, and even started vomiting.

At a local hospital, doctors discovered potentially toxic levels of clonidine in their blood. They treated the patients for low blood pressure and within 48 hours, all their symptoms resolved.

Police eventually discovered the drug in the restaurant’s starch and traced it to the neighboring restaurant. The two perpetrators were convicted and sentenced to one year in prison, the report says.

Toxicologist Wendy Klein-Schwartz says the criminals probably chose clonidine because it’s a potent drug that takes only a tiny amount to cause serious symptoms. “They wouldn’t need to put a lot [of the drug] into the eggplant so people probably wouldn’t notice it. It wouldn’t change the taste,” she says. “That’s just my guess.”