Speculation has reached fever pitch that storied Age journalist John “Sly” Silvester will join his colleague Andrew Rule at News Limited, after Rule’s bombshell defection to the Herald Sun yesterday.

Silvester and Rule have been inseparable at Fairfax since Rule’s hiring by inaugural Sunday Age editor Bruce Guthrie and have teamed up to pen the wildly-successful (and self-published) Underbelly series of books that have proven a cash cow for both the authors and the Nine Network.

“Sly isn’t clearing out his desk just yet,” one Fairfax insider said cryptically this morning.

Like Rule, Silvester is understood to be on extremely good terms with senior Herald Sun management, including editor-in-chief Phil Gardner and deputy editor Jill Baker. Baker, Rule and Silvester once shared a newsroom bonhomie that is said to persist years later. Silvester has previously served as a columnist on the Sunday Herald Sun, and Rule on The Sun.

Silvester has a long history at News Limited, beginning his career as a police reporter at the then-Sun in 1979 and returning as a crime scribe for the Herald Sun when it was launched in 1991. He moved to Fairfax in 1993 and has remained there ever since.

A move away from Fairfax could also mean the end of Silvester’s regular “Sly of the Underworld” slots on 3AW, which is owned by Fairfax. Rule also previously worked at AW, building contacts and kicking his career into overdrive as the producer of the Ross & John Breakfast program in the early ’90s before joining The Sunday Age.

They have also recently collaborated on The Age‘s popular page-two Naked City column, which this week will be penned by Silvester alone. However, tomorrow’s edition could prove its swansong, with no indication inside the paper of its future beyond this week.

“I don’t think ‘half-Naked City‘ is really going to fly,” the insider told Crikey this morning.

Fairfax moles confirm Rule — a former track work jockey turned Gold Walkley winner — pushed the escape button after colleague Karen Kissane was anointed as Paola Totaro’s successor as Fairfax European correspondent two weeks ago. He will join Andrew Bolt as an associate editor at the paper, with a roving brief to investigate Melburnian malfeasance in all its forms. Daily Telegraph editor Garry Linnell is believed to have been crucial in wooing Rule across to News’ Southbank HQ.

The departure comes on the eve of tomorrow’s re-launch of The Age‘s Saturday edition, in which Rule was expecting to be heavily promoted as a star columnist alongside other Media House pillars including Silvester and Caroline Wilson.

The departure of Rule and the possible defection of Silvester will add to concerns over mismanagement at The Age, which has seen profits and circulation slide over the last five years as real estate ads and editorial talent steadily evaporated.

Among a string of highlights in Rule’s storied career, observers say his relentless pursuit of the ice-cold Jennifer Tanner murder case and his fingering of the nation’s most senior indigenous figure at the time, Geoff Clark, on r-pe allegations ranked highly.

Rule last left Fairfax to temporarily assist with his wife Di Rule’s unsuccessful bid to win back Jeff Kennett’s former state seat of Burwood for the Liberals in 2002. Rule emerged with just 44.9% of the two-party preferred vote.