An uneven comedy-adventure about a fictional 15th century Korean king and his faithful assistant who form a Sherlock Holmes and Dr. Watson-type detective team, “The King’s Case Note” is at least a refreshing change from traditional Korean costume spectacles in which all things royal are treated with utmost respect and solemnity. Beginning brightly with goofy slapstick, irreverent humor and a dastardly plot to overthrow the monarch, the film squanders its early success in a second half marred by pedestrian pacing and ho-hum action scenes. This second feature by director Moon Hyun-sung (“As One,” 2014) has notched an impressive 1.3 million domestic admissions since opening April 26. A more muted reception appears likely in North America as the film widens May 5 from its April 28 limited release.
Based on a comic strip by Heo Yoon-mi that ran in South Korea’s popular Wink magazine in 2012 and 2013, “The King’s Case Book” quickly establishes a winning odd-couple dynamic. First to enter the frame is Yoon Yi-seo (Ahn Jae-hong, “The Sunshine Boys”), a brilliant but socially inept young scholar reporting for his first day of work in the court of Joseon dynasty ruler King Yejong (Lee Sun-kyun, “A Hard Day”). While Yoon displays all the characteristics audiences would expect from a nervous newbie entering such hallowed halls, the king is an entirely different and very appealing creation. A charismatic type who’s more interested in science, criminal psychology and the art of illusion than the usual business of state, Yejong has more in common with Tony Stark and Bruce Wayne with than the long line of stolid Korean movie monarchs who’ve preceded him.
Following a highly amusing sequence in which Yoon demonstrates his photographic memory while Yejong raps him on the head with a riding crop, the youngster is hired as Royal Historian. In practice that means standing five paces away from the ruler and chronicling his every word and action. The screenplay zips along nicely as Yoon gradually learns that the real task at hand is helping his boss discover who’s behind a plot to overthrow him and install his 12-year-old nephew, Prince Jaseong (Uhm Ji-sung), as puppet king.
The first clues arrive at the autopsy of a man whose head spectacularly catches fire in a busy street. In fine Sherlockian style Yejong (who performs the postmortem) deduces that trouble’s brewing in the iron ore-rich northern province of Hamgil and that local official Nam Geon-hee (Kim Hie-won) is pulling conspiratorial strings.
The investigation leads the duo to a lake where a “ghost fish” connected to prophecies of royal doom has suddenly appeared. The chemistry between Lee and Ahn is at its best when the King drags Yoon onto a boat to tackle the creature head-on. At this point the sleuths also come across Sunhwa (Kyung Soo-jin), a female psychic caught up in Nam’s diabolical plot.
But after setting out an array of nifty threads, the story stitches them together in less-colorful fashion. While not exactly falling apart, the second hour largely lacks the free-wheeling spirit of what’s gone before, and there’s a distinct dip in the frequency and quality of the Yoon-Yejong buddy banter. Director Moon executes some decent chase scenes, but swordplay sequences rarely rise above the serviceable. Promising supporting characters including Sunhwa and royal bodyguard Black Cloud (Jung Hae-in) are underused.
Despite its loss of mojo “Case Book,” has just enough heft to arrive at the finish line in reasonable shape. Providing valuable assists in an impressive tech package are d.p. Kim Dong-young’s attractive widescreen visuals and a rousing orchestral score by historical epic specialist Kim Tae-seong (“The Admiral: Roaring Currents,” “War of the Arrows”).