Exactly how this story came to be is something I can't discover online. My guess would be that Dixon had planned to continue with Catman had he not been offered the opportunity to produce the 'Air Hawk and the Flying Doctor' as a daily strip (which he made a great success, as shown by its longevity). But he had named the next Catman story, and may well have started working on it. If so, having a partial Catman story he could work on in his spare time and use to generate a bonus payment from, if the daily strip didn't work. One of the mysteries of Catman publishing is that there's never been an issue 13. Did Frew know this story might still arrive, so they kept the number free? And, if so, did they forget to do it?
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Giant Size Phantom 3 (Catman story only)