Screaming parallels are unmistakably vociferous, distinctive voices within earshot.
Long-time League One leaders whose brutal implosion reverberated around crumbling ramparts during a disintegrating December.
Some 13 years later, the unpalatable mimicry is glaringly obvious.
Swansea represent an excruciating case study, a wailing harbinger foreboding those delving into the 2005-06 campaign. Trespassers have been warned.
Yet the similarities between Pompey’s infuriating plight at present and that experienced by Kenny Jackett during part of his Swansea reign is significant.
Jackett has reaped three promotions during a managerial career which sees him still revered at Millwall and Wolves, while retaining immense respect among those inside the game.
He was also denied successive promotions at Swansea in the midst of a remarkable mid-season capitulation, culminating in sixth-placing – and bundled into a play-off campaign.
On December 10, 2005, the Swans were three points clear at League One’s summit.
With 42 points from 21 fixtures and the largest goal difference by some considerable distance, Jackett’s men were undisputedly in pole position.
They subsequently collected three victories from their next 16 league outings, never again returningto such lofty heights during that campaign.
Admittedly, just four defeats occurred during that pivotal period, nonetheless 18 points were reaped from a possible 48. There was to be no clambering to their feet with renewed purpose.
Top spot was relinquished following Boxing Day defeat at Brentford. The season concluded with Swansea languishing a disappointing eight points adrift of automatic promotion.
Fast forward to 2019, with the Blues currently fourth in League One, six points short of second-placed Barnsley, fittingly today’s Fratton Park opponents.
The Tykes also lined-up against Jackett’s Swansea side for the 2006 League One Play-Off final at the end of that season.
Incidentally, it was a second Millennium Stadium visit of the campaign for the Swans, having won the Johnstone’s Paint Trophy the previous month over Carlisle.
Back to the present, though, and the Blues’ concerning downward trend has been evident since December, although precise pinpointing is difficult.
Certainly they haven’t registered a clean sheet in the 13 league matches following the 2-0 success over Southend on December 8.
There have also been just three League One wins during that timeframe, with victories arriving against 10-men Sunderland and Fleetwood.
The third was AFC Wimbledon, left bottom following a New Year’s Day defeat, signifying Jackett’s only league triumph of 2019.
In fact, since the turn of the year, Pompey have amassed seven points from 24 on offer ahead of this afternoon’s encounter with Barnsley.
The Tykes were 12 points behind following the meeting at Oakwell in mid-December. Now the South Yorkshire club are six points ahead and undefeated in 13 league fixtures.
The Blues were jettisoned by Luton from the top spot they occupied for three-and-a-half months, albeit on January 26 when Jackett’s men were distracted by FA Cup duty against QPR.
Today the gap between the Hatters is 10 points, with no game in hand for either.
Returning to May 2006, Jackett lifted his side sufficiently to defeat Brentford 3-1 on aggregate to reach the play-off final against Barnsley, vying for a place in the Championship.
With the match deadlocked at 2-2 after extra-time, the Swans’ Ade Akinfenwa and Alan Tate missed in a 4-3 shoot-out defeat. More league agony for Jackett.
Of the Tykes side that day, three are presently part of the club’s backroom set-up, with Dale Tonge assistant first-team coach to manager Daniel Stendel and likely to be present at Fratton Park today.
Bobby Hassell (Academy manager) and Martin Devaney (under-23s head coach) also remain.
Still, the winter malaise hasn’t merely affected Jackett sides in 2005-06 and 2018-19, with last term a notable addition.
Encouragingly, Pompey ended 2017 situated sixth in League One during what represented his maiden campaign at the helm.
An outstanding run of nine wins from 11 matches in all competitions stemmed from a Checkatrade Trophy encounter at Charlton in early November 2017.
Then arrived Danny Rose’s broken leg and an underwhelming January transfer window performance, specifically failure to strengthen the crucial midfield area.
Subsequently, Pompey lost six of their 10 league outings until the end of February, collecting just eight points.
January alone earned one point from 12 on offer as Jackett’s men tumbled into ninth, surrendering realistic play-off aspirations which had previously existed.
From March they recovered to four-successive victories and six undefeated, yet the charge was too late, having failed to capitalise in January.
This season, forming the backdrop to the increasingly-sparse form of late is the Checkatrade Trophy, a relative of the competition won by Jackett in April 2006.
On Tuesday evening, Pompey head to Bury striving to earn a place in the Wembley final against the winners of either Sunderland or Bristol Rovers.
History depicts how that Swansea side, irrespective of faltering league form, managed to claim the trophy, albeit the semi-final in those days being a two-legged affair.
Although, without question,Jackett’s priorities centred on promotion ambitions which weeks later would be devastated at the same Millennium Stadium venue.
Jackett never did lead the Welsh side into the Championship the following season, quitting in February 2007 with the team seventh. Ex-player Roberto Martinez was his replacement.
The former Welsh international instead masterminded Millwall to two League One play-off finals, winning the second, in addition to the 2013 FA Cup final semi-final against Wigan.
He then steered Wolves into the Championship at the first time of asking, with a record League One tally of 103 points.
Jackett, of course, has been here before, familiar challenges to negotiate within unpredictable terrain.
Mid-season capitulation has proven an infuriatingly companion on occasions.
But just as frequent have been promotion, silverware and play-off finals in Jackett's managerial career.