The formula stored for this lot is Saturn plus the cusp of the eighth house minus the Moon, and it is the one lot in this atlas that is not projected from the Ascendant. That single difference carries more practical weight than anything else on the page.
Every other lot here depends on the birth time. This one depends on the birth time and on the house system. The Ascendant is an observed quantity that all house systems agree about. The eighth cusp is not: Placidus, Regiomontanus, Alcabitius, Porphyry, Campanus, Koch and Equal will put it in different places from the same birth data, and away from the equator the disagreement can run to many degrees and can cross a sign boundary. Two astrologers with identical birth data and different software will get different Lots of Death and neither will have made a mistake.
The motion is roughly the Ascendant's, because an intermediate cusp circles the zodiac once a day as the Ascendant does, though not at a uniform rate. The Moon subtracts about 13 degrees 11 minutes a day and Saturn adds two minutes of arc, so the lot advances something in the order of 347 degrees a day, about one degree every four minutes.
The reporting rule is therefore stricter than for the rest of the table: a Lot of Death should never be given without naming the house system it was cast in.