In summer 1605 Garnet met with Robert Catesby, a member of the English nobility who, unknown to him, planned to assassinate the Protestant King James I.

He was taken to London and interrogated by the Privy Council, whose members included John Popham, Edward Coke and Robert Cecil, 1st Earl of Salisbury.

Imprisoned in the Tower of London, his conversations with fellow prisoner Edward Oldcorne were monitored by eavesdroppers, and his letters to friends such as Anne Vaux were intercepted.

Criticised for his use of equivocation, which Coke called "open and broad lying and forswearing", and condemned for not warning the authorities of what Catesby planned, he was sentenced to be hanged, drawn and quartered.

[2] He often dined with Sir John Popham, who as Lord Chief Justice was to preside over the trial of the Gunpowder Plotters, men whose association with Garnet would eventually prove so fateful.

[nb 1] Acquaviva had also given Garnet permission to print pro-Catholic literature, and so early the next year he met Southwell in London to discuss the establishment of a secret press, which was probably located somewhere around a former Augustinian hospital near Spitalfields.

[1] From a friend's window in Ludgate Hill, Garnet witnessed the November 1588 procession to a thanksgiving service at Old St Paul's Cathedral, celebrating the failed Spanish invasion.

Spain's actions gave Garnet much cause for concern, "For when we thought that there was an end to these disasters by which we are already nearly destroyed, our hope was suddenly turned to sorrow, and now with redoubled effort the overseers are pressing upon us".

In light of the Armada's destruction, he also wrote to the general to ask for advice on two versions of a proposed oath to allow Roman Catholics to swear their allegiance to the Queen.

[1] As a result of an almost disastrous meeting at Baddesley Clinton in 1591, when he and many others were almost captured together while renewing their vows, he reorganised the mission into eleven smaller groups, each assigned two weeks annually.

[11] Following Southwell's capture in June 1592, and the search of Anne Vaux and Eleanor Brooksby's rented house in Warwickshire, he wrote to Acquaviva to ask for an assistant who could succeed him as superior.

The castle's inhabitants were supported by Catholic alms and lived a relatively comfortable existence; Garnet was complimentary about Wisbech, calling it a "college of venerable confessors".

[18] In November he was with Anne Vaux (whose family he had been introduced to in summer 1586)[1] at White Webbs near Enfield, renewing the vows given on the Feast of the Presentation of Our Lady.

[23] Of the 1603 Bye Plot, revealed (with his blessing) to the Privy Council by two Catholic priests, he wrote that it was "a piece of impudent folly, for we know that it is by peaceful means that his Holiness and other princes are prepared to help us.

It was a message echoed by Archpriest George Blackwell, who commanded his priests never to attempt any such thing,[25] but it proved controversial; early in summer 1605 Garnet reported to Rome that English Catholics had reached "a stage of desperation".

[29] So Garnet wrote to Aquaviva, claiming to have prevented several outbreaks of violence, and of his suspicion that there was "a risk that some private endeavour may commit treason or use force against the King".

About 30 people made the journey west, including Everard Digby and his wife, and their secret chaplain Edward Oldcorne, and Nicholas Owen.

They received sustenance from their protectors through a small drinking straw hidden within the building's structure, but with no commode or drainage they were eventually forced by "customs of nature which must of necessity be done" to emerge from hiding, and were immediately captured.

Superficially, they treated him with respect, removing their hats and addressing him as "Mr Garnet", although they made fun of his relationship with Anne Vaux, claiming he was her lover, not her confessor.

[nb 4] Although it condemned lying, Garnet's treatise supported the notion that when questioned, for instance, on the presence of a priest in his house, a Catholic might "securely in conscience" answer "No" if he had a "secret meaning reserved in his mind".

The occasions on which a Catholic might legitimately use equivocation, he supposed, were limited, but such replies could be taken as an example of insincerity or deviousness—especially to the king's council, who may not have wanted to see Garnet prove his case.

[42] His jailer, a man named Carey, was employed by Waad to gain the priest's trust, offering to relay letters to his nephew in the Gatehouse Prison.

[41] Although Garnet told Vaux that the Council's evidence constituted nothing but "presumptions", insufficient for a state trial, early in March he confessed, possibly as a result of torture.

[44] Despite his claims to have been horrified by Catesby's plan, his declaration, which admitted that he had "dealt very reservedly with your Lordships in the case of the late powder action",[45] gave the government proof that he had prior knowledge of the plot, and in their view, he was therefore guilty of misprision of treason.

He was taken to the Guildhall by closed coach; an unusual method, considering prisoners were usually walked to trial, though the authorities may have had some concern about support from a sympathetic crowd.

In attendance were King James (hidden from public view) and several courtiers including Lady Arbella Stuart and Catherine Howard, Countess of Suffolk.

He was accused of having conspired with Catesby on 9 June 1605 to kill the king, his son, and to "alter and subvert the government of the kingdom and the true worship of God established in England".

Coke called Garnet "a doctor of five Ds, namely, of dissimulation, of deposing of princes, of disposing of kingdoms, of daunting and deterring of subjects, and of destruction".

Francis Tresham's deathbed letter, which claimed that Garnet had played no part in the so-called Spanish Treason,[nb 6] was read aloud.

When the government lied and told him they had captured Tesimond, he wrote an apologetic letter to the priest regarding the nature of their conversation the previous year.