Dragons aren’t HBO’s only weapon to win the streaming wars. The Last of Us, a post-apocalyptic zombie-adventure series based on the video game of the same name, drew a record 4.7 million viewers across linear and HBO Max platforms Sunday night, according to Nielsen and first-party data. Those numbers gave the new series a rare honor — The Last of Us earned the second-largest debut audience since Boardwalk Empire premiered in 2010, behind only House of the Dragon. While Sunday night’s numbers are indeed impressive, the Sunday viewership for an HBO series typically represents just 20 to 40 percent of an episode’s total gross audience, meaning the ratings are likely to more than double as audiences catch up to a show in the days and weeks to come. The press release uses Euphoria as an example of just that phenomenon. The Last of Us’s debut audience was nearly double that of season two of Zendaya’s teen melodrama, with the latter going on to average 19.5 million viewers per episode in the United States. Social-media engagement was high, too, with the series trending No. 1 on Twitter both domestically and globally. It looks The Last of Us will get most of us to tune in.