The third outing of the drama spin-off began with 466,000 (2.17%) with its audience slowly declining to 433,000 (2.1%) in the final 15-minutes. The show was slightly under the channel's sot average for the year so far of 494,000 (2.28%).
The new series got underway last week with a double bill. The first episode, at 9pm gained 810,000 (3.5%) with the following edition at 9.55pm on 703,000 (4%).
Last night's episode had been preceded by the Tomb Raider film Cradle of Life, which pulled in 611,000 (3.17%) at 7.10pm.
Over the main part of peaktime viewing BBC3 locked horns with ITV's own youth entertainment channel ITV2.
Despite being repeats the channel's coverage of The X Factor pulled in the viewers. A re-run of the main show at 8pm drew 774,000 (3.80%) with a further 111,000 watching on ITV2+1. The Xtra Factor at 9pm had 421,000 (1.95%) with 59,000 watching the timeshifted option at 10pm.
Five US was also in a strong position at 9pm with CSI: NY claiming 336,000 (1.5%) with an extra 28,000 watching on Five US+1.
Earlier in the evening Sky One's Gladiators, at 7pm, which reached the semi-final stage, drew 429,000 (2.41%).
Viewers still haven't tired of Midsomer Murders as a two-hour repeat of the ITV1 show at 8pm pulled in a sizeable 6.6m (27.2%). BBC1 didn't have much of a response as BBC1's new Pacific Abyss could managed only 3.9m (16.5%) over an hour. The corporation improved the situation at 9pm as Britain From Above gained 4.5m (18.2%).
The situation for Channel 4's Make Me a Christian took a turn for the worse at 7pm as just 589,000 (2.9%) tuned in with just 43,000 watching on C4+1. The show was down from 697,000 (3.5%) that watch last week.
C4 also found itself bottom of the terrestrial pile at 8pm with Wife Swap at 8pm on just 1.8m (7.6%). The show attracted 142,000 on C4+1. Just ahead was BBC2's Top Gear on 1.9m (8%). Five was head and shoulders above its nearest rivals with the 2004 film Hellboy on 2.8m (11.9%).
All hours shares for Sunday 17 August 2008: BBC1 - 30%, ITV1 - 14.1%, BBC2 - 8.9%, Five - 5.5%, C4 - 5.2% (C4+1 - 0.8%), multichannel - 35.5%.
Peaktime (6pm to 10.30pm) shares: BBC1 - 19.7%, ITV1 - 24.6%, C4 - 6.9% (C4+1 - 0.8%), BBC2 - 8.9%, Five - 8.6%, multichannel - 30.5%.