A Matter of Grooves

I found a retractable ballpoint pen lying disassembled across the wooden desk. Its internal ratcheting cam had slipped off the primary track, wedging the tiny compression spring sideways. Rather than forcing the barrel closed, I took a seat and traced the alternating ridges molded along the inner casing. Using the tip of an unfolded paperclip, I nudged the notched collar back into alignment until the teeth settled flush into their slots. Pressing the plunger produced a clean, firm snap—the mechanism catches tension exactly as designed now.